acid

Pronunciation

• IPA: /ˈæs.ɪd/^[1]

Etymology

It is borrowed from French acide or directly from Latin acidus (“sour, sharp”),^[2][3][4] from acēre “to be sour”,^[2][3][5] from Proto-Indo-European *ak- (“to be sharp, pierce”).^[2][4] It is related to acrid, acerbic and acetic.^[3][6]

Earliest recorded meaning

Sour, tasting of vinegar: 1626, in Francis Bacon's Sylva Sylvarum, where sorrel is called “a cold and acid herb”.^[7][3][8]

Semantic evolution

The noun is from the 1690s (1696 in Barnhart).^[2][3] At first it was any sour substance, and in chemistry it was gradually defined more precisely from the early 18th century, so that it now covers compounds that do not taste sour.^[2][8] The figurative sense, sharp or biting, is from 1775,^[2][7] and of intense colours by 1916.^[2][7] Acid drop is by 1835,^[2] and the acid test, testing gold with nitric acid, is American English from 1881.^[2][8] Acid rain is recorded by 1859, of England.^[2] The slang sense “LSD” is from 1966.^[2]

Timeline

• 1626 – sour.^[7][3]
• 1696 – noun.^[3]
• 1775 – figurative, biting.^[2][7]
• 1859 – acid rain.^[2]
• 1881 – acid test.^[2]
• 1966 – slang, LSD.^[2]

Modern meaning

Noun

1. (chemistry) A substance that reacts with a base to form a salt, turns litmus red, and in water gives hydrogen ions.
2. A sour substance.
3. (slang) LSD.

Adjective

1. Sour in taste.
2. Containing or relating to acid.
3. Sharp or sarcastic: acid remarks.

Word family

• acidly
• acidness
• acidy
• acid-fast
• acidhead
• acidic
• acidify
• acidimeter

Related words

• acetic
• acidity
• acrid
• acerbic
• acute

References

1. ^ Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
2. ^ a b c d e f g h i j k l m n o Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ Pearsall, Judy, ed. (1998), The New Oxford Dictionary of English, Oxford: Clarendon Press
6. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c d e Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
8. ^ a b c Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press