Etymologically
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acidic

This is the current revision of this entry, as edited by bogdan on 31 October 2026 at 22:15. This address is a permanent link to this version.
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Pronunciation

  • /əˈsɪd.ɪk/[1]

Etymology

It is formed from English acid + -ic.[2][3][4][5][6] The base comes from Latin acidus (“sour, tart, sharp”), from aceō (“to be sour”),[4][2][7] from Proto-Indo-European *ak- (“to be sharp”).[4][7] The OED compares the earlier adjectives acid and acidy.[2]

Earliest recorded meaning

Merriam-Webster dates the word to 1866, in the sense "acid-forming".[5] The OED's first record is from 1868, in Dana's System of Mineralogy, of a chemical element that combines with oxygen or sulphur to form a salt with a basic element.[2]

Semantic evolution

Etymonline explains that the word began in geology, where geologists used it of the "acid" element, such as silicon, in certain salts, as the opposite of basic.[4] From 1876 it described igneous rock rich in silica.[2][3] From 1873 it meant "having the properties of an acid", later defined as having a pH below 7.[2][3] Figurative uses came in the 20th century: of speech, cutting or bitter (1936), and of colour, strikingly bright or garish (1971).[2]

Timeline

  • 1866 – acid-forming.[5] The OED's first record of this sense is from 1868.[2]
  • 1873 – chemistry, having the properties of an acid.[2]
  • 1876 – geology, of igneous rock, rich in silica.[2]
  • 1936 – of speech, cutting, bitter.[2]
  • 1971 – of colour, bright, garish.[2]

Meanings

Adjective

  1. Containing or having the properties of an acid; having a pH below 7: acidic soil.[8][5][2][3]
  2. (chemistry) Forming an acid, as an element or an oxide that yields an acid in water.[8][5][2]
  3. (geology) Of igneous rock, rich in silica.[2][3]
  4. Of remarks, sharp or biting.[2]
  5. Of colour, strikingly bright or garish.[2]

Word family

  • nonacidic
  • unacidic

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  4. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  5. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  6. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  7. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  8. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins