Online Etymology Dictionary

base (v.): "to place on a foundation," 1841, from base (n.). Related: Based; basing.
baseball (n.): in the modern sense, 1845, American English, from base (n.) + ball (n.1). Earlier references, such as in Jane Austen's "Northanger Abbey," refer to the game of "rounders," of which baseball is a more elaborate variety. Legendarily invented 1839 by Abner Doubleday in Cooperstown, N.Y. Base was used for "start or finish line of a race" from 1690s; and the sense of "safe spot" found in modern children's game of tag can be traced to 14c. (the sense in baseball is from 1868).
baseboard (n.): 1854, from base (n.) + board (n.1).
Basel: city in northwestern Switzerland, founded 44 C.E. as Robur (from Latin roburetum "oak grove"); renamed 374 as Basilia (from Greek basilea "royal") when it became the "royal" fortress of Valentinian I.
baseless (adj.): c. 1600, from base (n.) + -less. Related: Baselessly; baselessness.
baseline (n.): also base-line, 1750, originally in surveying, from base (n.) + line (n.). Baseball diamond sense is from 1867. Baseline estimate in use by 1983.
basement (n.): "lowest story of a building except the cellar," 1730, from base (v.) + -ment.
baseness (n.): 1550s, from base (adj.) + -ness.
bash (v.): "to strike violently," 1640s, perhaps of Scandinavian origin, from Old Norse *basca "to strike" (source also of Swedish basa "to baste, whip, flog, lash," Danish baske "to beat, strike, cudgel"); or the whole group might be independently derived and echoic. Figurative sense of "abuse verbally or in writing" is from 1948. Related: Bashed; bashing.
bash (n.): "a heavy blow," 1805, from bash (v.). Meaning "an attempt" is attested by 1948. On a bash "on a drunken spree" is slang from 1901, which gave the word its sense of "party."
bashaw (n.): 1530s, earlier Englishing of pasha.
basher (n.): 1882, agent noun from bash (v.).
bashful (adj.): 1540s, with -ful + baishen "to be filled with consternation or dismay" (mid-14c.), from Old French baissier "bring down, humiliate" (see abash). An unusual case of this suffix attached to a verbal stem in the passive sense. Related: Bashfully; bashfulness (1530s).
basic (adj.): 1832, originally in chemistry, from base (n.) + -ic.
BASIC: computer language, 1964, initialism (acronym) for Beginners' All-purpose Symbolic Instruction Code; invented by Hungarian-born U.S. computer scientist John G. Kemeny (1926-1992) and U.S. computer scientist Thomas E. Kurtz (b.1928).
basically (adv.): 1903, from basic (adj.) + -ly (2).
basics (n.): "rudiments or fundamentals of anything," by 1934, from basic. Also see -ics. Phrase back-to-basics was in use by 1975.
basil (n.): aromatic shrubby plant, early 15c., from Old French basile (15c., Modern French basilic), from Medieval Latin basilicum, from Greek basilikon (phyton) "royal (plant)," from basileus "king" (see Basil). So called, probably, because it was believed to have been used in making royal perfumes. In Latin, confused with basiliscus (see basilisk) because it was supposed to be an antidote to the basilisk's venom.
Basil: masc. proper name, from Latin Basilius, from Greek Basileios "kingly, royal," from basileus "king," which is of unknown origin, possibly from a language of Asia Minor (compare Lydian battos "king").
basilica (n.): 1540s, from Latin basilica "building of a court of justice," and, by extension, church built on the plan of one, from Greek (stoa) basilike "royal (portal)," the portico of the archon basileus, the official who dispensed justice in Athens, from basileus "king" (see Basil). In Rome, applied specifically to the seven principal churches founded by Constantine.
basilisk (n.): c. 1300, from Latin basiliscus, from Greek basiliskos "little king," diminutive of basileus "king" (see Basil); said by Pliny to have been so called because of a crest or spot on its head resembling a crown.
The basilisk has since the fourteenth century been confused with the Cockatrice, and the subject is now a complicated one. [T.H. White, "The Bestiary. A Book of Beasts," 1954]
Its breath and glance were said to be fatal. The South American lizard so called (1813) because it, like the mythical beast, has a crest. Also used of a type of large cannon, throwing shot of 200 lb., from 1540s.
basin (n.): "large shallow vessel or dish," c. 1200, from Old French bacin (11c., Modern French bassin), from Vulgar Latin *baccinum, from *bacca "water vessel," perhaps originally Gaulish. Meaning "large-scale artificial water-holding landscape feature" is from 1712. Geological sense of "tract of country drained by one river or draining into one sea" is from 1830.
basis (n.): 1570s, "bottom or foundation (of something material)," from Latin basis "foundation," from Greek basis "a step, stand, base, that whereon one stands," from bainein "go, step" (see come). Transferred and figurative senses (of immaterial things) are from c. 1600.
bask (v.): late 14c., basken "to wallow (in blood)," with loss of middle syllable, from Old Norse baðask "to bathe oneself," reflexive of baða "bathe" (see bathe). Modern meaning "soak up a flood of warmth" is apparently due to Shakespeare's use of the word in reference to sunshine in "As You Like It" (1600). Related: Basked; basking.
Baskerville: typeface style, 1802 (the type was created in the 1750s), named for John Baskerville (1706-1775), British type-founder and printer.
The initial version were cut by John Handy under Baskerville's watchful eye. The result is the epitome of Neoclassicism and eighteenth-century rationalism in type -- a face far more popular in Republican France and the American colonies than in eighteenth-century England, where it was made. [Robert Bringhurst, "The Elements of Typographic Style," 1992]
basket (n.): early 13c., from Anglo-French bascat, origin obscure despite much speculation. On one theory from Latin bascauda "kettle, table-vessel," said by the Roman poet Martial to be from Celtic British and perhaps cognate with Latin fascis "bundle, faggot," in which case it probably originally meant "wicker basket." But OED frowns on this, and there is no evidence of such a word in Celtic unless later words in Irish and Welsh, counted as borrowings from English, are original.
basket case (n.): 1919, American English, originally a reference to rumors of quadriplegics as a result of catastrophic wounds suffered in World War I (the military vehemently denied there were any such in its hospitals), from basket (n.) + case (n.2). Probably literal, i.e., stuck in a basket, but basket had colloquial connotations of poverty (begging) and helplessness long before this. Figurative sense of "person emotionally unable to cope" is from 1921.
basketball (n.): 1892, American English, from basket + ball (n.1). The game was invented 1891 by James A. Naismith (1861-1939), physical education instructor in Springfield, Massachusetts, U.S.
basking (adj.): 1742, present participle adjective from bask (v.). Basking shark is recorded from 1769.
Basque: 1817 (adj.), 1835 (n.), from French, from Spanish vasco (adj.), from vascon (n.), from Latin Vascones (Vasconia was the Roman name for the up-country of the western Pyrenees), said by von Humboldt to originally mean "foresters" but more likely a Latinized version of the people's name for themselves, euskara or eskuara.
This contains a basic element -sk- which is believed to relate to maritime people or sailors, and which is also found in the name of the Etruscans .... [Room, "Placenames of the World," 2006]
Earlier in English was Basquish (1610s, noun and adjective); Baskles (plural noun, late 14c.); Baskon (mid-15c.).
bass (adj.): late 14c., of things, "low, not high," from Late Latin bassus "short, low" (see base (adj.)). Meaning "low in social scale or rank" is recorded from late 14c. Of voices and music notes, from mid-15c. (technically, ranging from the E flat below the bass stave to the F above it), infuenced by Italian basso. Meaning "lowest part of a harmonized musical composition" is from mid-15c. Meaning "bass-viol" is from 1702; that of "double-bass" is from 1927.
bass (n.): freshwater fish, c. 1400 corruption of Middle English baers, from Old English bærs "a fish, perch," from Proto-Germanic base *bars- "sharp" (source also of Middle Dutch baerse, Middle High German bars, German Barsch "perch," German barsch "rough"), from PIE root *bhar- "point, bristle" (see bristle (n.)). The fish was so called for its dorsal fins. For loss of -r-, see ass (n.2).
basset (n.): type of short-legged dog, 1610s, from French basset, from Old French bas "low" (see base (adj.)) + diminutive suffix.
bassinet (n.): "wicker cradle," 1854, from French bassinet "a little basin," diminutive of bassin (see basin), or, as per Klein, the English word is from French bercelonette, double diminutive of berceau "cradle," altered by bassin "basin." Middle English had bacinet "hemispherical helmet" (c. 1300).
basso: in various musical terms borrowed from Italian, "bass, a bass voice," from Italian basso, from Late Latin bassus (see bass (adj.)).
bassoon (n.): 1727, from French basson (17c.), from Italian bassone, augmentative of basso (see bass (adj.)). Compare balloon (n.); also see -oon.
bast (n.): "inner bark of the linden tree," Old English bæst, a general Germanic word (cognate with Old Norse, Old Saxon, Middle Dutch, Old High German, German bast) of uncertain origin.
bastard (n.): "illegitimate child," early 13c., from Old French bastard (11c., Modern French bâtard), "acknowledged child of a nobleman by a woman other than his wife," probably from fils de bast "packsaddle son," meaning a child conceived on an improvised bed (saddles often doubled as beds while traveling), with pejorative ending -art (see -ard). Alternative possibly is that the word is from Proto-Germanic *banstiz "barn," equally suggestive of low origin.

Not always regarded as a stigma; the Conqueror is referred to in state documents as "William the Bastard." Figurative sense of "something not pure or genuine" is late 14c.; use as a vulgar term of abuse for a man is attested from 1830. As an adjective from late 14c. Among the "bastard" words in Halliwell-Phillipps' "Dictionary of Archaic and Provincial Words" are avetrol, chance-bairn, by-blow, harecoppe, horcop, and gimbo ("a bastard's bastard").
bastardize (v.): 1610s, "to identify as a bastard," from bastard (q.v.) + -ize. The figurative sense, "to make degenerate, debase" is earlier (1580s), probably because bastard also was serving as a verb meaning "to declare illegitimate" (1540s). Related: Bastardized; bastardizing; bastardization.
bastardy (n.): early 14c., "condition of illegitimacy," from Anglo-French and Old French bastardie, from bastard (see bastard). As "begetting of bastards, fornication" from 1570s.
baste (v.1): "sew together loosely," c. 1400, from Old French bastir "build, construct, sew up (a garment), baste, make, prepare, arrange" (12c., Modern French bâtir "to build"), probably from Frankish or some other Germanic source, from Proto-Germanic *bastjan "join together with bast" (source also of Old High German besten; see bast).
baste (v.2): "to soak in gravy, moisten," late 14c., of unknown origin, possibly from Old French basser "to moisten, soak," from bassin "basin" (see basin). Related: Basted; basting.
baste (v.3): "beat, thrash," 1530s, perhaps from the cookery sense of baste (v.2) or from some Scandinavian source (such as Swedish basa "to beat, flog," bösta "to thump") akin to Old Norse beysta "to beat," and related to Old English beatan (see beat (v.)).
baster (n.): 1520s, "one who bastes meat," from baste (v.2); from 1726 as "heavy blow," from baste (v.3).
Bastille (n.): 14c. Paris prison destroyed by revolutionaries on July 14, 1789, French, literally "fortress, tower" (see bastion).
bastinado (n.): 1570s, from Spanish bastonada "a beating, cudgeling," from baston "stick," from Late Latin bastum (see baton).
bastion (n.): 1560s, from Middle French bastillon, diminutive of Old French bastille "fortress, tower, fortified, building," from Old Provençal bastir "build," perhaps originally "make with bast" (see baste (v.1)).
bat (n.1): "a stick, a club," Old English *batt "cudgel," perhaps from Celtic (compare Irish and Gaelic bat, bata "staff, cudgel"), influenced by Old French batte, from Late Latin battre "beat;" all from PIE root *bhat- "to strike." Also "a lump, piece" (mid-14c.), as in brickbat. As a kind of paddle used to play cricket, it is attested from 1706.

Phrase right off the bat is 1888, also hot from the bat (1888), probably a baseball metaphor, but cricket is possible as a source; there is an early citation from Australia (in an article about slang): "Well, it is a vice you'd better get rid of then. Refined conversation is a mark of culture. Let me hear that kid use slang again, and I'll give it to him right off the bat. I'll wipe up the floor with him. I'll ---" ["The Australian Journal," November 1888].
bat (n.2): flying mammal (order Chiroptera), 1570s, a dialectal alteration of Middle English bakke (early 14c.), which is probably related to Old Swedish natbakka, Old Danish nathbakkæ "night bat," and Old Norse leðrblaka "leather flapper" (for connections outside Germanic, see flagellum). If so, the original sense of the animal name likely was "flapper." The shift from -k- to -t- may have come through confusion of bakke with Latin blatta "moth, nocturnal insect."

Old English word for the animal was hreremus, from hreran "to shake" (see rare (adj.2)), and rattle-mouse is attested from late 16c., an old dialectal word for "bat." Flitter-mouse (1540s) is occasionally used in English (variants flinder-mouse, flicker-mouse) in imitation of German fledermaus "bat," from Old High German fledaron "to flutter."

As a contemptuous term for an old woman, perhaps a suggestion of witchcraft (compare fly-by-night), or from bat as "prostitute who plies her trade by night" [Farmer, who calls it "old slang" and finds French equivalent "night swallow" (hirondelle de nuit) "more poetic"].
bat (v.1): "to move the eyelids," 1847, American English, from earlier sense of "flutter as a hawk" (1610s), a variant of bate (v.2) on the notion of fluttering wings. Related: Batted; batting.