Origin and history of LSD

in reference to a crystalline organic compound, 1934, from the -lys- in hydrolysis (thus from Greek lysis "a loosening, a dissolution," from lyein "to loosen, dissolve;" from PIE root *leu- "to loosen, divide, cut apart") + the first syllable of ergot (a fungus from which the chemical was first obtained) + -ic.

Old English sur "sharp and acidic to the taste, tart, acid, fermented," from Proto-Germanic *sura- "sour" (source also of Old Norse surr, Middle Dutch suur, Dutch zuur, Old High German sur, German sauer), from PIE root *suro- "sour, salty, bitter" (source also of Old Church Slavonic syru, Russian syroi "moist, raw;" Lithuanian sūras "salty," sūris "cheese"). French sur "sour, tart" (12c.) is a Germanic loan-word.

The meaning "harsh of temper, crabbed, having a peevish disposition" is from early 13c. The sense in whisky sour (1885) is "with lemon added" (1862). Sour cream is attested from 1855. Sour grapes as a figure of the tendency to disparage something only because it is unattainable, from the Aesop fable of the hungry fox, is by 1836.

The Fox, when hee cannot reach the grapes, saies they are not ripe. ["Outlandish Proverbs Selected," London: 1640]

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."