opaque (English)

Where does "opaque" come from?

The word 'opaque' descends from the Latin adjective 'opacus', which originally meant 'shaded' or 'dark'. By way of Middle English and later reinforcement from Middle French, the term evolved from describing literal shadows to characterizing things that are difficult to see through or understand. It remains a distant cousin to the French 'ubac', both sharing an ancient history tied to the Latin root for shade.

Full etymology tree

• opaque (English), 'Neither reflecting nor emitting light.'
  • inherited opake (Middle English), 'dark, shaded, unlit'
    • borrowed opacus (Latin), 'shaded, darkened; in the shade'
      • inherited *op-wākos (Proto-Italic)
        • compound *h₁epi (Proto-Indo-European), 'on, at, near'
        • compound *h₁weh₂- (Proto-Indo-European), 'to be/become empty'
  • influence opaque (Middle French), 'opaque'

Direct ancestors

• opake (Middle English)
• opacus (Latin)
• opaque (Middle French)
• ubac (English)

Updated July 2026

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