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.

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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

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noun

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

verb

1. to make opaque

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

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

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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”

Explanation

Use the adjective opaque either for something that doesn't allow light to pass through (like a heavy curtain) or for something difficult to understand (like bureaucratic gobbledygook). Opaque is from a Latin word meaning "dark," and that was its original sense in English, but it now means literally "not transparent" or metaphorically "hard to understand; unclear": "Some of his sentences are really opaque." It used to be spelled opake, which made the pronunciation clearer, but we then borrowed the more opaque French spelling. Come to think of it, English spelling is often pretty opaque, which makes it hard for learners of the language to master.

Example Sentences

Last September, Human Rights Watch urged African nations to reject the "opaque deals", arguing that they were "designed to instrumentalise human suffering".

From BBC • May 20, 2026

During argument, Sotomayor pointed to findings that Google’s interfaces themselves were confusing and opaque.

From Slate • May 20, 2026

The music biz feels more opaque to you?

From Los Angeles Times • May 11, 2026

Private-markets lending has surged in popularity with investors but stumbled in recent months after worries over valuations, opaque structures and exposures to struggling business sectors such as software.

From The Wall Street Journal • May 6, 2026

Scars crossed and disfigured his face with jagged lines across his forehead and down the length of one cheek, and his eyes were opaque and unseeing.

From "Gathering Blue" by Lois Lowry

Related Words

• blurred
• cloudy
• dirty
• dull
• frosty
• gloomy
• hazy
• impenetrable
• murky
• thick