opaque

• opake (obsolete)

From Middle English opake, from Latin opacus (“shaded, shady, dark”) (of unknown origin), later reinforced from Middle French opaque. Doublet of ubac.

• (UK) IPA^(key): /əʊˈpeɪk/

• Audio (Southern England)

  (file)

• (US) IPA^(key): /oʊˈpeɪk/
• Rhymes: -eɪk

opaque (comparative more opaque or opaquer, superlative most opaque or opaquest) (see usage notes)

1. Neither reflecting nor emitting light.
   • 1968, Isaac Asimov, Photosynthesis, Basic Books, Inc., page 60:

     We have agreed that heat is energy to begin with. Light is also a form of energy for when absorbed by any opaque substance it turns completely into heat.

2. Allowing little light to pass through, not translucent or transparent.
3. (figuratively) Unclear, unintelligible, hard to get or explain the meaning of.
4. (figuratively) Obtuse, stupid.
5. (computing) Describes a type for which higher-level callers have no knowledge of data values or their representations; all operations are carried out by the type's defined abstract operators.

• The comparative opaquer and superlative opaquest, though formed following valid rules for English, are much less common than more opaque and most opaque and seem to occur more frequently in poetry.
• Most opaque has been more common than opaquest for at least two centuries and 50 to 100 times more common in the last two decades, according to this Google Ngram comparison.

• (antonym(s) of “physically”): see-through, translucent, transparent
• (antonym(s) of “figuratively”): clear, obvious, oblique, bright, brilliant

• opacity

opaque (plural opaques)

1. (obsolete, poetic) An area of darkness; a place or region with no light.
   • 1745, Edward Young, Night-Thoughts, section I:

     Through this opaque of Nature and of Soul, / This double night, transmit one pitying ray, / To lighten, and to cheer.

2. Something which is opaque rather than translucent.

opaque (third-person singular simple present opaques, present participle opaquing, simple past and past participle opaqued)

1. (transitive) To make, render (more) opaque.

• blur
• cloud

• translucent

• Douglas Harper (2001–2024) “opaque”, in Online Etymology Dictionary.
• Webster's Seventh New Collegiate Dictionary, Springfield, Massachusetts, G.&C. Merriam Co., 1967

Borrowed from Latin opācus (“shaded, shady, dark”), itself of unknown origin. Doublet of ubac.

• IPA^(key): /ɔ.pak/

• Audio

  (file)

opaque (plural opaques)

1. opaque

   Antonyms: transparent, translucide

• opacifier
  • opacification
• opacité
• opaquement

• → Romanian: opac
• → Turkish: opak

• “opaque”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

opaque m or f (plural opaques)

1. opaque

opaque

1. inflection of opacar:
   1. first/third-person singular present subjunctive
   2. third-person singular imperative