Dictionary.com
Thesaurus.com
Synonyms

opaque

American  
[oh-peyk] / oʊˈpeɪk /

adjective

  1. not transparent or translucent; impenetrable to light; not allowing light to pass through.

    Synonyms:
    muddy, cloudy, murky
  2. not transmitting radiation, sound, heat, etc.

  3. not shining or bright; dark; dull.

  4. hard to understand; not clear or lucid; obscure.

    The problem remains opaque despite explanations.

  5. dull, stupid, or unintelligent.


noun

  1. something that is opaque.

  2. Photography. a coloring matter, usually black or red, used to render part of a negative opaque.

verb (used with object)

opaqued, opaquing
  1. Photography. to cover up blemishes on (a negative), especially for making a printing plate.

  2. to cause to become opaque.

opaque British  
/ əʊˈpeɪk /

adjective

  1. not transmitting light; not transparent or translucent

  2. not reflecting light; lacking lustre or shine; dull

  3. not transmitting radiant energy, such as electromagnetic or corpuscular radiation, or sound

  4. hard to understand; unintelligible

  5. unintelligent; dense

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. photog an opaque pigment used to block out particular areas on a negative

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. to make opaque

  2. photog to block out particular areas, such as blemishes, on (a negative), using an opaque

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
opaque Scientific  
/ ō-pāk /
  1. Resistant to the transmission of certain kinds of radiation, usually light. Metals and many minerals are opaque to light, while being transparent to radio waves and neutrinos.

  2. Compare translucent transparent


Other Word Forms

  • opaquely adverb
  • opaqueness noun
  • subopaque adjective
  • subopaquely adverb
  • subopaqueness noun

Etymology

Origin of opaque

First recorded in 1375–1425; late Middle English opake, from Latin opācus “shaded”

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Customers buy tokens to use AI services - but the amount of tokens needed for each task is sometimes opaque.

From BBC • Apr. 1, 2026

Where things get the most opaque with finances is with alternative investments that don’t have the same kind of reporting as stocks and bonds.

From MarketWatch • Mar. 30, 2026

Investors are yanking money out of the opaque funds, lifting withdrawals to record highs.

From The Wall Street Journal • Mar. 27, 2026

As with private equity, the grading of private loans is more opaque than for their public market counterparts.

From Barron's • Mar. 18, 2026

Soon she was a fragile pile of opaque bones, with yellowed nails and no monthly blood.

From "Dreaming in Cuban" by Cristina García