- Labium is the Latin
word for "lip." It is a neuter noun, so the plural (for a pair of lips) is labia. But here is where usage can be confusing. There is also a Latin feminine noun for "lip"; singular labia, plural labiae. In anatomy, the neuter noun is used, so that the two sets of opposing lips of the vulva (even though this is strictly a female organ) are properly called the labia majora (the larger, external lips) and the labia minora (the smaller, internal lips). A related Greek verb is laphyssein, "to swallow greedily, to devour." It would seem that these words, all pertaining to lips, originated in imitation of the sound produced by lapping fluid into the mouth, labor is anotherword for parturition, the process of giving birth to a baby, and comes closer in meaning to the Latin noun labor, “a troublesome effort or suffering," than the common use of the word today as almost a synonym for ordinary work. The ancient meaning was implied in Jesus' entreaty, "Come unto me, all ye that labor and are heavy laden, and I will give you rest" (Matthew 11:28). laboratory sounds as though it was conceived as a name for any place where work was done. But this is not the sense in which the word was used in ancienttimes or asit is used now. A place where people work at plucking chickens or at hammering out horseshoes is not a laboratory. The word comes from the Latin elaborare, "to work out, as a problem, with great pains." An old English spelling was elaboratory and designated a place where learned effort was applied to the solution of scientific problems. We have simply dropped the "e." labyrinth is a near borrowing of the Greek labyrinthos, "a large structure with intricate passages intersecting each other." In Greek mythology, the Athenians were at one time sorely oppressed by Minos, the king of Crete, who exacted from them an annual tribute of seven young men and seven maidens. These unfortunate youngsters were condemned by Minos to be devoured by the voracious Minotaur, a monsterwith a man's body and a bull's head. That the Minotaur was fed but once a year accounts for his appetite. The victims were placed in a labyrinth where the monster roamed and from which there was no escape. A stop was put to this egregious practice by Theseus, the heroic son ofthe king of Athens. His ingenious plan was to use a clew, "a ball ofstring or yarn,” which was kindly furnished by Ariadne, King Minos' daughter, who had fallen in love with Theseus. By unwinding the thread along his path, Theseus could readily find his way out of the labyrinth after killing the Minotaur. This explains our use of “clue" for whatever leads to the solution of a problem. In anatomy, "labyrinth" designates the lateral mass of the ethmoid bone and also the internal ear, both of which contain intricate passages. laceration is a near borrowing ofthe Latin laceratio, "a tearing or a mangling." The word now serves for any cut incurred as an injury, but it retains its sense of forceful trauma. A cut made by a careful surgeon is an incision, not a laceration. lacertus is a Latin word that to the Romans meant both "a muscle" and "a lizard," presumably because of the fancied resemblance in shape. More specifically, the reference was to the biceps muscle in the upper arm. Now, in anatomy, "lacertus" designates the fibrous expansion or attachment of certain muscles, particularly the biceps brachii and the lateral rectus muscle ofthe eye. lacrimal originated in the Indo-European dakru, "a tear, as from a weeping eye." The same word was used by the Greeks. In archaic Latin this became dacruma, but in classical Latin the "d" was changed to “1" under Sabine influence, and to the Romans "a tear" was either lacruma or lacrima. The Old English derivative was taehher, whence the English "tear." In anatomy, we putthis together when we say, "The lacrimal duct conveys the tears." 129 lacteal larva An alternative spelling is "lachrymal," which was an aberration arising from the Medieval Latinists' custom of changing "c" to "ch" preceding an "r" (as in "pulchritude"); the "i" became "y" simply as a graphic variant. So, "lacrimal" is the correctspelling, even though poetically we persist in using "lachrymose" to describe a person given to weeping. lacteal refers to the fine, endothelial-lined lymphatic channels that convey fat-laden lymph from the absorptive intestinal mucosa. The appearance of such lymph suggests that of milk, hence the origin ofthe term in the Latin lacteus, "milky." lactic acid was originally discovered in sour milk (Latin lac, "milk"). lactose is the sugar (a disaccharide that on hydrolysis yields glucose + galactose) that naturally occurs in milk. For an explanation of the suffix "-ose," see glucose. lacuna is the Latin word for "a gap or hollow, a place where water tends to collect," such as a pit or pond. In anatomy, the term is used to refer to any similar configuration; for example, the tiny pits in compact bone. These minute apertures in bone, having been first described in 1691 by Clopton Havers (1657- 1702), an English physician and anatomist, are also known as "Haversian canals." The lining of certain ducts, notably the urethra, is marked by small pits or lacunae. lagophthalmos is an inability to completely close the eyelids. The Greek lagos means "hare," a rabbit-like animal distinctive in being bom with eyes open. lambdoid refers to whatever may be fancied in the shape of the Greek letter lambda (A), which looks like an inverted "V." Thus, the lambdoid suture of the skull and the lambdoid incision for gaining access to the epigastric viscera were so named. An occasional error in spelling or pronunciation is to omit the first "d." lamina is the Latin word for "a thin plate," and lamella is the diminutive form meaning "a little, thin plate." A host of anatomic structures incorporate these terms in their names. For example, the plate-like dorsal arches of the vertebrae are called laminae, and the operation whereby they are removed is laminectomy. lancet is a slightly shortened form ofthe French lancette, which was derived from the Latin lancea, "spear." A lancet is "a little spear." To lance a lesion, such as a boil, is to spear it. The Lancet, long one of the world's most respected medical journals, is said to have been given its name in 1823 by its founding editor Dr. Thomas Wakley (1795-1862) to assert his intent "to lance abscesses ofthe medical body politic," i.e., to expose charlatanism and shoddy medical practice, lanolin is a fatty subtance obtained from the wool of sheep. The name was concocted by combining the Latin lana, "wool," + oleum, "oil." As an emollient or unguent it is usually made up as a hydrous emulsion. It is commonly incorporated in cosmetic lotions purported to soften or "moisturize” the skin, lanugo is the Latin word for "down, meaning the small, fine hairs of plants." The lanugo of the fetus is the downy excrescence that appears aboutthe fifth month of gestation, laparotomy comes from the Greek lapara, "the soft parts of the body between the rib margins and the hips," i.e., the flanks or loins. This, in turn, is related to laparos, "slack, loose, or relaxed." The suffix comes from the Greek tome, "a cutting." "Laparotomy" was introduced as a term for an operation in 1878 by Thomas Bryant (1828-1914), an English surgeon. Purists insist that "laparotomy" should be used to designate only incisions in the flanks and not for those elsewhere in the abdomen, but the currency of usage has stifled their argument. Similarly, laparoscopy (+ Greek skopein, "to view") has been disdained in some circles as an improper term for looking into the abdominal cavity by means of an optical instrument, even though this instrument is inserted through the "soft parts" of the abdomen. This procedure was long known in the United States as "peritoneoscopy," but "laparoscopy," as the procedure is widely known and used in Europe and japan, has rapidly gained supremacy, larva is Latin for "mask or ghost." The Romans used the word to designate the specter ofthe dead, which they conceived as having the spirit but not the actual form of the living creature it represents. In this sense the term became applied to an early phase in the life 130 larynx laxative of an insect or parasite before its true form became apparent (which is known by the Latin word imago). Regressing to its figurative sense, we may make reference to a "larval" form of a disease when we mean an early, undefined phase in its development. The same can be said for “larval" ideas, larynx is a direct borrowing of the Greek term for "the upper part of the windpipe." This is related to the Greek verb lary[n]ggixd, "I bawl or bellow," from which the term laryngismus was derived, as an allusion to the crowing sound issuing from a spastic larynx, laser is an acronym, i.e., a word, preferably pronounceable, formed from initial letters or parts of a name or phrase, in sequence. "Laser" stands for Light Amplification by Stimulated Emission ofRadiation. A laser is a device that converts, within a medium of crystal or gas, incident electromagnetic radiation of mixed frequencies to a discrete, coherent, highly amplified emission of visible light. As such, the laser is a means of transmitting intense, focused energy, and it is thus used therapeutically for coagulation and ablation oftissues. Lassa fever was so named to commemorate the town in Nigeria where a missionary nurse was fatally stricken by the disease in 1969. latent is a slightly abbreviated form of the Latin adverb latenter, "secretly," and is related to the intransitive verb latere, "to lie hidden or concealed." Thus, latent syphilis is a "hidden" form of the disease, latex is the Latin word for "a liquid or fluid substance," especially that from a hidden source, such as water from a spring or sap from a tree (see latent). In botany, latex is the milky fluid extracted from certain plants, notably the rubber tree, which congeals on exposure to air or heat. In the laboratory, latex is any emulsion of fine particles of plastic substance that passively carry an adsorbed antigen and can be coagulated by certain constituents of serum. Thus, we have a "latex fixation test" for rheumatoid factor in serum and for human chorionic gonadotropin in urine, lathyrism is a morbid condition that may result from ingestion of seeds of certain leguminous plants of the genus Lathyrus, which includes a variety of peas. The toxic ingredient is (1-aminoproprionitrile that inhibits the enzyme lysyl oxidase. Symptoms include paresthesia, hyperesthesia, pain, and spastic paraplegia. The familiar "sweet pea" is a climbing herb (Lathyrus odoratus) cultivated for the fragrance of its varicolored flowers. The lesson here: "Inhale, but don't eat." laudable pus was a name once given to seropurulent effusion from a wound, in the mistaken beliefthatsuch discharge was a sign of healing. Only later was it recognized as a sign of infection. Laudable? Hardly. laudanum is an old designator of tincture of opium. Some scholars assertthatthe name is a derivative of the Greek ladonon, the resin obtained from an oriental shrub (not the poppy plant) that was known to the Persians as ladan. The claim is that this substance was confused with poppy juice, the source of opium. There is a more plausible, if not laudable, explanation. "Laudanum" was introduced into the pharmacopoeia by Theophrastus Bombastus von Hohenheim (1493-1541), a Swiss physician who named himself Paracelsus to indicate that he was on a par with, if not superior to, the renowned Celsus. He claimed he had a secret remedy (which may or may not have contained opium) that he considered laude dignum, "worthy of praise." It is curious to note that, much later, heroin (q.v.) was given its name because it was thought to be similarly laudable. laughing gas was the name given to nitrous oxide in 1800 by Sir Humphry Davy (1778- 1829), the remarkable English surgeonapothecary-chemist who investigated the curious psychotropic properties of the gas when it was inhaled. Davy went on to discover and isolate numerous elements, among them sodium, potassium, chlorine, and fluorine. Some say Sir Humphry's greatest discovery was his assistant, Michael Faraday. lavage comes from the Latin lavare, "to wash." "Gastric lavage" is another way ofsaying "a stomach washing." A lavatory, of course, is "a place for washing." laxative is derived from the Latin laxare, "to extend, widen, open, or release." In the sense of loosening or relaxing the bowel, the term was not used by the Romans but emerged in 131 laying on of hands lenticular the Middle Ages, perhaps because those were such costive times. laying on of hands (see king's evil) Lazarus syndrome encompasses the anxiety, depression, and sense of alienation sometimessuffered by survivors of cardiorespiratory resuscitation (Ann Intern Med. 1972;76:135). These are patients who have been brought back from the perilous brink of death. The allusion, of course, is to the brother of Mary and Martha, whom fesus raised from the dead (John 11:1-44). There is another unrelated biblical Lazarus, the diseased beggar shunned by the rich man who should have known better (Luke 16:19-31). From this Lazarus is derived lazaretto, an esoteric term for a hospital harboring victims of contagious disease or for a way-station, on land or afloat, to accommodate subjects of quarantine. The name was originally applied to a hospital maintained in Venice by the Church of Santa Maria de Nazaret. A translation of "Lazarus" is "God has helped." In more timely reference to the recent anthrax scare, a lazaretto also served as a facility for fumigating letters supposedly contaminated when written by persons known or suspected of being afflicted by contagious disease. lecithin comes from the Greek lekithos, "the yolk of an egg." This name for the mono-aminemonophosphatide was suggested by its early discovery in carp eggs. Its Greek origin would indicate the "c" in "lecithin" should be pronounced as "k," yet almost invariably it is given a voiceless fricative "s" sound. leech is the common name for a bloodsucking worm ofthe class Hirudinea, but it also was once used to designate a physician. In fact, the latter meaning came first, being derived from the Old English leece, "one who heals." Today, in Iceland a physician is a laeknir, in Finland a laakari, and in Sweden a lakare. The Dano-Norwegian is laege, the Polish is lekarz. The bloodsucking annelid worm, in bygone days, was used therapeutically, the idea being thatthe worm would consume corrupting substances from an inflamed lesion. Hence, the worm was give the name of "the healer" (Ann Intern Med. 1988; 109:399). Still later, "leech" became an epithet for a person who clung to and extracted sustenance from another. In days of yore, a "leechbook" was a manual of empiric remedies. Legionella is a genus of gram-negative aerobic bacilli capable of causing a pneumonia-like disease in man (legionellosis). The disease was first recognized and its cause discovered consequent to an outbreak that occurred among delegates to an American Legion convention in Philadelphia in 1976. The organisms proliferated in a contaminated airconditioning system of a large hotel. leiomyoma is contrived by linking the Greek leios, "smooth," + mys, "muscle," + oma, "swelling"; hence, "a Smooth Muscle tumor." Such tumors commonly occur in the muscular wall of the uterus and were, and sometimes still are, mistakenly called "fibroids." lemniscus is an almost direct borrowing of the Greek lemniskos, "a woolen ribbon or bandage," related to lemnos, "wool." In anatomy, a lemniscus is a band or bundle of neural fibers. lens is the Latin word (the genitive is lends) for the bean-like seed that we call "lentil." The only lens familiar to the ancients was that of the eye, and itwas given the name ofthe bean because ofitssize and shape; itstransparency had nothing to do with its naming. For those well acquainted with the lens ofthe eye but unfamiliar with lentil beans, examine the beans on your next visit to a grocery; you'll see the allusion is apt. The Greek word for the lentil bean is phakos, and by the same analogy that has been applied to the Latin lens, we have phako- as a combining form pertaining to the lens ofthe eye. Aphakia is an absence of the lens. Oddly, a phakoma is a minute, pale tumorseen microscopically in the retina in cases of tuberous sclerosis; also it is the term applied to a patch of myelinated nerve fibers seen in the retina in neurofibromatosis. Other terms include the misspelled phaco-, as in phacocele (+ Greek kele, "hernia"), denoting a dislodged, misplaced lens. lenta is the feminine form ofthe Latin adjective meaning "slow or sluggish." Subacute bacterial endocarditis was once known as "endocarditis lenta" because of its typically slow, lingering course. lenticular can describe whatever is shaped like a lentil bean (see lens), particularly the nucleus 132 lentigo leukoplakia found in the corpus striatum of the brain. It has nothing to do with the lens ofthe eye and was so named simply because ofits shape. lentigo is the Latin word for "freckle," related to the Latin lens, lentis, the legume bearing the small flattened bean we call "lentil." Indeed, what the dermatologist calls "lentigo" looks a lot like a freckle. It is a small, brown spotin the skin, resulting from the deposition ofmelanin pigment by an active focus of melanocytes near the basal layer of the epidermis. But to the dermatologist there is an important distinction. A freckle comes from exposure to the actinic rays of the sun, whereas lentigines (the plural) can be the result of various other causes. Conversely, a patch of white, depigmented skin is called vitiligo, a term derived from the Latin vitium, "a blemish or defect." To vitiate is to defile or make faulty. Incidentally, the suffix -igo, of Latin origin, once was used in a number of terms denoting conditions of disease in man, animals, plants, and even metals. Those medical terms that have survived are mostly related to dermatology, e.g., lentigo, vitiligo, intertrigo, and impetigo. Surviving terms related to other systems are vertigo and, as a slight variant, lumbago. leontiasis is a rare form of hyperostosis, occurring as a fibrous dysplasia in younger persons or as a feature of Paget’s disease of bone in the elderly, wherein the facial bones enlarge, giving the victim a countenance suggesting that of a lion. Leo, leonis is Latin for "lion." Beethoven is depicted in his later years as having a somewhat leonine countenance, and it has been suggested the great composer might have been a victim of Paget's disease, which also could have contributed to his deafness. leprosy comes from the Greek lepros, "scaly, rough, or mangy," hence, "the scaly disease." Gerhard Hansen (1841-1912), a Norwegian physician, correctly described the causative organism, Mycobacterium leprae, and the condition is now properly known as Hansen's disease. In ancient Greece, what we now know as leprosy probably did not exist. The "scaly disease" ofthe Greeks more likely was psoriasis. Aretaeusthe Cappadocian described leprosy accurately in the second century A.D., but he called it "leontiasis" because of the facial deformity. There then followed a confusion ofnames, and in the translation ofArabic writings the Greek lepra became attached to what is now recognized as Hansen's disease. The term "leprosy," then, doubly deserves to be abandoned, not only because of its unjust connotation of despicableness, but also because it has been misplaced nosologically. lepto- is a combining form taken from the Greek leptos, "fine, slender, or delicate." Thus, the leptomeninges (+ Greek meni[n]gx, "membrane") are the thin, delicate membranes, comprising both the pia and the arachnoid, that envelope the brain and spinal cord. Leptospira (+ Greek speira, "coil") is a genus of finely coiled spirochetes, lesbianism (see tribadism) lesion comes from the Latin laesio, "an attack or injury," which is related to the verb laedere, "to strike, hurt, or wound." lethal (see lethargy; also mortal) lethargy is a state of overpowering apathy or drowsiness. The term is taken from the Greek lethargos, "forgetful." In Greek mythology, Lethe was the name of a river that flowed in the netherworld of Hades. The souls of the dead were obliged to drink of its water and so become oblivious of everything said or done during theirspan on earth. One might assume thatthe word lethal, meaning deadly, was of analogous origin. Not quite. "Lethal" is from the Latin letum, meaning "death or destruction." The "h" got put in the English word in the 17th century because of confusion with the Greek lethe, "oblivion." Our word, then, should be "letal," but no one would recognize it as such. leuk-, leuko- is sometimes spelled "leuco-" (although “k" is preferred to "c") and is a combining form, usually a prefix, taken from the Greek leukos, "white," and also "light, bright, brilliant, and clear." The apostle Luke, patron saint of physicians, owes his name to the same source. leukemia is marked by neoplastic proliferation of any one of the species of leukocyte. The term combines leuko- + Greek aima, "blood." leukoplakia is characterized by white patches or plaques on a mucous membrane (leuko- + Greek plakoeis, "flat, broad"). 133 leukorrhea ligament leukorrhea is a white vaginal discharge (leuko-