acid (English)

Where does "acid" come from?

The word 'acid' traces its origins back to the Proto-Indo-European root *h₂eḱ-, meaning 'sharp.' This evolved into the Latin verb aceō ('to be sour') and the adjective acidus, which eventually entered modern English via the French acide. Over centuries, the term has expanded from its purely culinary roots of tasting 'sour' to encompass chemical properties and even modern musical styles.

Full etymology tree

• acid (English), 'Sour, sharp, or biting to the taste; tart; having the taste of vinegar.'
  • borrowed acide (French), 'acid, acidic, sour, tart'
    • inherited acidus (Latin), 'sour, tart, acid, bitter'
      • derived aceō (Latin), 'to be sour'
        • inherited *h₂éḱ-eh₁ye-ti (Proto-Indo-European)
          • derived *h₂eḱ- (Proto-Indo-European), 'sharp'
      • suffix -idus (Latin), 'tending to'

Direct ancestors

• h₂eḱ- (Proto-Indo-European)
• acide (French)
• acidus (Latin)
• agita (English)
• acetic (English)

Updated July 2026

Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris