Online Etymology Dictionary

etymology: late 14c., from Gk. etymologia, from etymon "true sense" (neut. of etymos "true," related to eteos "true") + logos "word." In classical times, of meanings; later, of histories. Latinized by Cicero as veriloquium.
wormwood: c.1400, folk etymology of O.E. wermod "wormwood," related to vermouth, but the ultimate etymology is unknown. Cf. O.S. wermoda, Du. wermoet, O.H.G. werimuota, Ger. Wermut. Weekley suggests wer "man" + mod "courage," from its early use as an aphrodisiac. Figurative use, however, is usually in reference to its bitter aftertaste. Perhaps because of the folk etymology, it formerly was used to protect clothes and bedding from moths and fleas. "A medecyne for an hawke that hath mites. Take the Iuce of wormewode and put it ther thay be and thei shall dye." ["Book of St. Albans," 1486]
cockroach: 1624, folk etymology of Sp. cucaracha "chafer, beetle," from cuca "kind of caterpillar." Folk etymology is from caca "excrement."
"A certaine India Bug, called by the Spaniards a Cacarootch, the which creeping into Chests they eat and defile with their ill-sented dung" [Capt. John Smith, "Virginia," 1624].
lounge (v.): 1508, from Scot., of uncertain origin, perhaps from Fr. s'allonger (paresseusement) "to lounge about, lie at full length," from O.Fr. alongier "lengthen," from L. longus "long." Another etymology traces it through obsolete lungis (n.) "slow, lazy person" (c.1560), from M.Fr. longis, a generic application of Longinus, supposed to be the name of the centurion who pierced Christ's side with a spear in John xix.34. Popular etymology associated the name with long (adj.). The noun in the sense of "comfortable drawing room" is first recorded 1881; in the sense of "couch on which one can lie at full length," 1830. Lounge lizard is from 1912, originally in reference to men who hung around in tea rooms to flirt.
bidet: 1630, from Fr., of unknown etymology. Originally in Fr. "a small horse, a pony," thus "a vessel on a low narrow stand, which can be bestridden for bathing purposes."
piepowder: 1220, "wayfarer, itinerant merchant, etc.," folk etymology alteration of M.L. pede-pulverosus, lit. "dusty-footed."
pogo stick: 1921, of uncertain etymology. Pogo as a leaping style of punk dance is attested from 1977.
hangnail: 1678, probably folk etymology from O.E. agnail "a corn on the foot," from PIE *angh- "tight, painfully constricted, painful."
Tijuana: from the name of a Diegueño (Yuman) village, written Tiajuan in 1829; deformed by folk-etymology association with Sp. Tia Juana "Aunt Jane."
Bern: Swiss capital, probably originally from PIE root *ber- "marshy place," but by folk etymology from Ger. Bär "bear."
Acheron: 1580s, fabled river of the Lower World in Gk. mythology. The name probably means "marsh-like" (cf. akherousai "marshlike water"); the derivation from akhos "woe" is considered folk etymology.
mace (2): "spice made from dry outer husk of nutmeg," late 14c., from O.Fr. macis (in Eng. taken as a plural), sometimes said to be a scribal error for L. macir, a red spicy bark from India, but OED finds this etymology unlikely.
Zyklon: 1926, from Ger. Zyklon, commercial name of a type of hydrogen cyanide, of unknown etymology, but it is the usual German form of the word cyclone. Originally used as a pesticide and fumigant.
Muppet: Trademark (U.S.) Sept. 26, 1972, claiming use from 1971, but in print from Sept. 1970. Name coined by creator Jim Henson (1936-1990), who said, despite the resemblance to marionette and puppet (they have qualities of both), it has no etymology; he just liked the sound.
croft: O.E. croft "enclosed field," of unknown etymology. Crofter is 1799, originally Scottish.
johnny-cake: 1739, Amer.Eng., of unknown origin, perhaps from Shawnee cake, from the Indian tribe. Folk etymology since 1775, however, connects it to journey cake.
Cyrus: L., from Gk. Kyros, from O.Pers. Kurush, a name of unknown etymology. In Heb., Koresh, and in that form taken c.1990 by Wayne Howell of Texas, U.S., when he became head of the Branch Davidian cult there.
Gullah: "of or pertaining to blacks on the sea-islands of Georgia and South Carolina," 1739 (first attested as a male slave's proper name), of uncertain origin. Early 19c. folk etymology made it a shortening of Angola (homeland of many slaves) or traced it to a W. African tribal group called the Golas.
Herefordshire: O.E. Herefordscir, from Hereford (958), lit. "ford suitable for the passage of an army." Probably so-called in ref. to the Roman road passing over the Wye River. Herford in Germany has the same etymology. As the name for a type of cattle, first bred there, it is attested from 1789.
Uriah: masc. proper name, in O.T., the Hittite husband of Bathsheba; of non-Hebrew (possibly Horite) origin, but explained by folk etymology as Heb. Uriyyah, lit. "flame of the Lord." Uriah Heep, character from Dickens' "David Copperfield" (1850) sometimes is invoked as the type of a hypocritically humble person.
subscript: 1704, "that which is written underneath," from L. subscriptus, pp. of subscribere "write underneath" (see subscribe for etymology and sense development).
piggyback: 1838, probably a folk-etymology alteration of pick pack (1565), which perhaps is from pick, a dial. variant of pitch (v.).
delicate: late 14c., from L. delicatus "alluring, delightful, dainty," also "addicted to pleasure," of unknown origin; related by folk etymology (and perhaps genuinely) to deliciæ "a pet," and delicere "to allure, entice." Meaning "feeble in constitution" is c.1400; that of "easily broken" is recorded from 1560s.
gentian: O.E., from L. gentiana, said by Pliny to be named for Gentius, king of ancient Illyria who discovered its properties. This is likely a folk-etymology, but the word may be Illyrian, since the suffix -an frequently occurs in Illyrian words.
flannel: 1503, from Welsh gwlanen "woolen cloth," from gwlan "wool." Not a universally accepted etymology; some suggest an Anglo-Fr. dim. of O.Fr. flaine "a kind of coarse wool."
Lilith: female evil spirit, in medieval Heb. folklore the first wife of Adam, from Heb. Lilith, from Akkad. Lilitu, which is connected by folk etymology with Heb. laylah "night."
baba: kind of plum cake, 1827, from Fr. baba (19c.), said by Fr. etymology dictionaries to be from Polish baba.
jackanapes: c.1449, "a monkey," also "an impertinent, conceited fellow;" apparently from Jack of Naples, but whether this is some specific personification or folk etymology of jack (n.) + ape is unknown.
pennyroyal: herb, 1530, alteration by folk etymology of Anglo-Fr. puliol real; for second element see royal; first element ultimately from L. puleglum "thyme."
mongoose: "snake-killing ichneumon of India," 1698, perhaps via Port., from an Indic language (cf. Mahrathi mangus "mongoose"), probably ult. from Dravidian (cf. Telugu mangisu, Kanarese mungisi). The form of the Eng. word altered by folk-etymology.
headlong: 1482, from hed "head" + suffix -ling (see grovel). Altered by folk etymology on pattern of sidelong, etc.
rickettsia: parasitic organism, 1919, named 1916 in Mod.L. by H. da Rocha-Lima in honor of U.S. pathologist H.T. Ricketts (1871-1910), who first identified it in 1909 and died of typhus as a result of his contact with it. The bacteria causes typhus and Rocky Mountain spotted fever, but is unrelated by pathology or etymology to rickets (q.v.), which is the result of vitamin D deficiency.
hearken: O.E. heorcnian, from base of hieran (see hear). Harken is the usual spelling in U.S. and probably is better justified by etymology.
Chamorro: indigenous people of Guam and the Marianas Islands, from Sp. Chamorro, lit. "shorn, shaven, bald." Supposedly because the men shaved their heads, but the name also has been connected to native Chamoru, said to mean "noble," so perhaps Chamorro is a Sp. folk etymology.
banausic: "merely mechanical," coined 1845 from Gk. banausikos "pertaining to mechanics," from banausos "artisan, mere mechanical," hence (to the Greeks) "base, ignoble;" perhaps lit. "working by fire," from baunos "furnace, forge" (but Klein dismisses this as folk etymology and calls it "of uncertain origin").
Bombay: city in western India, from Port., and popularly explained as Port. bom bahia "good bay," but that seems folk etymology (for one, the adj. is masc. and the n. is fem.), and the more likely candidate is the local Mumbadevi "Goddess Mumba," a Hindu deity worshipped there. The city's name officially changed to Mumbai in 1995.
Elohim: a name of God in the Bible, 1605, from Heb., pl. (of majesty?) of Eloh "God," a word of unknown etymology, perhaps an augmentation of El "God," also of unknown origin. Generally taken as singular, the use of this word instead of Yahveh is taken by biblical scholars as an important clue to authorship in the O.T.
Bruce: A Norman name, but etymology from Brix (place in La Manche, Normandy) is now considered doubtful ["Dictionary of English Surnames"]. Originated in Britain with Robert de Bruis, a baron listed in the Domesday Book. His son, a friend of David I, king of Scotland, was granted by him in 1124 the lordship of Annandale, and his second son Robert founded the Scottish House of Bruce.
patch (2): "fool, clown," 1549, perhaps from It. pazzo "fool," which is possibly from O.H.G. barzjan "to rave." Form perhaps infl. by folk-etymology from patch (1), on notion of a fool's patched garb.
costume: 1715, art term, from Fr., from It., from L. consuetudo "custom," and essentially the same word as custom but arriving by a different etymology. From "customary clothes of the particular period in which the scene is laid," meaning broadened by 1818 to "any defined mode of dress." Costume jewelry is first attested 1933.
rue (n.): "perennial evergreen shrub," 1382, from O.Fr. rue, earlier rude, from L. ruta "rue," probably from Gk. rhyte, of uncertain etymology, originally a Peloponnesian word. The bitter taste of its leaves led to many punning allusions to the noun form of rue (v.).
Essene: 1553, member of a Jewish sect (first recorded 2c. B.C.E.), from L., from Gk. Essenoi, of disputed etymology, perhaps from Heb. tzenum "the modest ones," or Heb. hashaim "the silent ones." Klein suggests Syriac hasen, pl. absolute state of hase "pious."
G-string: 1878, geestring, "loincloth worn by American Indian," originally the string that holds it up, etymology unknown. The spelling with G (1891) is perhaps from influence of violin string tuned to a G (in this sense G string is first recorded 1831). First used of women's attire 1936, with reference to strip-teasers.
Pegasus: winged horse in Gk. mythology, late 14c., from L., from Gk. Pegasos, usually said to be from pege "spring, font" (pl. pegai), especially in "springs of Ocean," near which Medusa was said to have been killed by Perseus (Pegasus sprang from her blood). But this may be folk etymology, and the suffix -asos suggests a pre-Gk. origin.
corduroy: 1780, Amer.Eng., probably from cord + obs. 17c. duroy, a coarse fabric made in England. Folk etymology is from *corde du roi "the king's cord," but this is not attested in Fr., where the term for the cloth was velours à côtes. Applied in U.S. to a road of logs across swampy ground (1822).
bizarre: c.1648, from Fr. bizarre "odd, fantastic," originally "handsome, brave," from Basque bizar "a beard" (th notion being of the strange impression made in France by bearded Sp. soldiers); alternative etymology traces it to It. bizarro "angry, fierce, irascible," from bizza "fit of anger."
shore (v.): mid-14c., "to prop, support with a prop;" of obscure etymology though widespread in W.Gmc.; cf. M.Du. schooren "to prop up, support," O.N. skorða (n.) "a piece of timber set up as a support."
sequoia: large American coniferous tree, 1866, from Mod.L., tree genus name given by Endlicher (1847), in honor of Sequoya (1760-1843), Cherokee man who invented a system of writing for his people's language, whose name is from Cherokee (Iroquoian) Sikwayi, a word of unknown etymology. Popularly also called Wellingtonia, the name given by Lindley (1853).
subscription: 1409, "piece of writing at the end of a document," from M.Fr. subscription, from L. subscriptionem (nom. subscriptio) "anything written underneath, a signature," from pp. stem of subscribere (see subscribe for etymology and sense development).
carminative: 1665, from L. carminat-, pp. stem of carminare "to card."
"A medical term from the old theory of humours. The object of carminatives is to expel wind, but the theory was that they dilute and relax the gross humours from whence the wind arises, combing them out like knots in wool." [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859-65]