Etymograph

English

acidhead

Acidhead comes from French acide ‘acid, acidic, sour, tart’, and goes back to Proto-Indo-European *h₂eḱ- ‘sharp’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eḱ-1‘sharp’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eḱéh₁yeti1reconstructed
  3. Proto-Italicc. 1500–700 BCE*akēō1reconstructed
  4. Latinc. 75 BCE–200 CEaceō1‘to be sour’
  5. Latinc. 75 BCE–200 CEacidus2‘sour, tart, acid, bitter’
  6. Frenchc. 1600–presentacide2‘acid, acidic, sour, tart’
  7. English1500–presentacid2‘LSD’
  8. Englishtodayacidhead2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin acidus
  2. 2 Wiktionary, English acidhead

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eḱ-Wiktionary, Latin acidus‘sharp’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eḱéh₁yetiWiktionary, Latin acidusreconstructed
  3. Proto-Italicc. 1500–700 BCE*akēōWiktionary, Latin acidusreconstructed
  4. Latinc. 75 BCE–200 CEaceōWiktionary, Latin acidus‘to be sour’
  5. Latinc. 75 BCE–200 CEacidusWiktionary, English acidhead‘sour, tart, acid, bitter’
  6. Frenchc. 1600–presentacideWiktionary, English acidhead‘acid, acidic, sour, tart’
  7. English1500–presentacidWiktionary, English acidhead‘LSD’
  8. EnglishtodayacidheadWiktionary, English acidhead

Linked words

through Proto-Indo-European *h₂eḱ- ‘sharp’

hear, edge, egg, ear, hammer, eager, axe, acute, vinegar, mediocre, oxide, acne, mediocrity, paragon, acupuncture, hark, exacerbate, acumen, acme, acuity, acacia, acrimony, exacerbation, acerbic, rosacea, acrid, 71 more

through Latin aceō ‘to be sour’

acetate, acyl, 22 more

through Latin acidus ‘sour, tart, acid, bitter’

acidity, roselle, 7 more

through French acide ‘acid, acidic, sour, tart’

margarine, 1 more

Today it means

noun A person who uses the hallucinogenic drug LSD.

Sources

Sources: Wiktionary, “acidhead”; the older steps come from the Wiktionary entry for Latin acidus. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *h₂eḱ- / acidhead

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