"bile, liver secretion," Old English galla (Anglian), gealla (West Saxon) "gall, bile," from Proto-Germanic *gallon "bile" (source also of Old Norse gall "gall, bile; sour drink," Old Saxon galle, Old High German galla, German Galle), from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall." Informal sense of "impudence, boldness" first recorded American English 1882; but meaning "embittered spirit, rancor" is from c. 1200, from the old medicine theory of humors.
"sourness, with roughness or astringency of taste," 1570s, from French acerbité, from Latin acerbitatem (nominative acerbitas) "harshness, sharpness, bitterness, sourness," literal and figurative (as in virus acerbitatis "the poison of malice"), from acerbus "bitter to taste, sharp, sour, tart," from Proto-Italic *akro-po- "sharp" (from PIE root *ak- "be sharp, rise (out) to a point, pierce").
The earliest use in English is figurative, of "sharp and bitter" persons. Of tastes, from 1610s. Latin acerbus is related to acer "sharp" as superbus "haughty" to super "above."
debilitating disease that affects the skin, 1560s, noun use of adjective scurvy "covered with scabs, diseased with scurvy, scorbutic" (early 15c.), a variant of scurfy. By 1560s the adjective also could mean "vile, low, mean, vulgar." Related: Scurvied.
It took on the narrower meaning of Dutch scheurbuik, French scorbut "scurvy," in reference to the disease characterized by swollen and bleeding gums, prostration, etc., perhaps from Old Norse skyrbjugr, which is perhaps literally "a swelling (bjugr) from drinking sour milk (skyr) on long sea voyages;" but OED has alternative etymology of Middle Dutch or Middle Low German origin, as "disease that lacerates the belly," from schoren "to lacerate" + Middle Low German buk, Dutch buik "belly."
late 13c., "strenuous, ardent, fierce, angry," from Old French aigre "sour, acid; harsh, bitter, rough; eager greedy; lively, active, forceful," from Vulgar Latin *acrus (source also of Italian agro, Spanish agrio), from Latin acer "keen, sharp, pointed, piercing; acute, ardent, zealous" (from PIE root *ak- "be sharp, rise (out) to a point, pierce").
Meaning "full of keen desire" (early 14c.) seems to be peculiar to English. The English word kept a secondary meaning of "pungent, sharp-edged" till 19c. (as in Shakespeare's "The bitter clamour of two eager tongues," in "Richard II"). Related: Eagerly; eagerness. Eager beaver "glutton for work" [OED] is from 1943, U.S. armed forces slang.
1690s, from acid (adj.); originally loosely applied to any substance having a sour taste like vinegar, in modern chemistry it was gradually given more precise definitions from early 18c. and is given to many compounds which do not have such a taste.
The slang meaning "LSD-25" first recorded 1966 (see LSD).
When I was on acid I would see things that looked like beams of light, and I would hear things that sounded an awful lot like car horns. [Mitch Hedberg, 1968-2005, U.S. stand-up comic]
Acid rock (type performed or received by people using LSD) is also from 1966; acid house dance music style is 1988, probably from acid in the hallucinogenic sense + house "dance club DJ music style."
According to Barnhart, the Gaelic is probably a loan-translation of Medieval Latin aqua vitae, which had been applied to intoxicating drinks since early 14c. (compare French eau de vie "brandy"). Other early spellings in English include usquebea (1706) and iskie bae (1580s). In Ireland and Scotland obtained from malt; in the U.S. commonly made from corn or rye. Spelling distinction between Scotch whisky and Irish and American whiskey is a 19c. innovation. Whisky sour is recorded from 1889.
mid-14c., "sternness, harshness," from Old French austerite "harshness, cruelty" (14c.) and directly from Late Latin austeritatem (nominative austeritas), from austerus "severe, rigid," a figurative use, in classical Latin "harsh, sour" (see austere).
From 1580s as "severe self-discipline, ascetic practices;" hence "severe simplicity, absence of adornment or luxuries," applied during World War II to national policies limiting non-essentials as a wartime economy.
[Austerity] stands just at the edge of that frame of mind which regards self-denial as good for its own sake ; it pushes simplicity of living and the refusal of pleasure beyond what is deemed necessary or helpful to right living by the great mass of those who are equally earnest with the austere in trying to live rightly. [Century Dictionary]
Also formerly in English "a shivering," especially as a symptom of disease or in reaction to a sour or bitter taste (1530s); "erection of the hairs on the skin" (1650s); "a ruffling as of water surface" (1630s). As a genre in film, 1934. Chamber of horrors originally (1849) was a gallery of notorious criminals in Madame Tussaud's wax exhibition. Other noun forms are horribility (14c., now rare or disused), horribleness (late 14c.), horridity (1620s), horridness (1610s).