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

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

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

See Examples For:

opaque opaqued opaquing

Five U.S. tech giants’ hidden debts soar to $1.65 trillion on opaque AI funding.

From MarketWatch ● Jul. 21, 2026

“They are proposing to deprioritize it at the same time that they are encouraging plans to invest in more complicated, opaque investments. It’s infuriating.”

From Salon ● Jul. 9, 2026

Washington slammed the missile test, with the State Department saying Beijing's "rapid and opaque nuclear weapons buildup is of great concern" and urging China to "engage in meaningful arms control discussions."

From Barron's ● Jul. 8, 2026

For the serious aficionado, there are intricate tactical breakdowns and opaque stats like expected goals.

From The Wall Street Journal ● Jul. 1, 2026

Red marble, its white veins illuminated in the light of the sun, which slowly vanished as the opaque glass doors groaned shut.

From "Throne of Glass" by Sarah J. Maas

The helmet ports were opaqued so there was no way to tell what expression went with the gesture.

From Sense of Obligation by Henry Maxwell Dempsey (AKA Harry Harrison)

"We're here first," Ihjel said, opaquing the ports and turning on the cabin lights.

From Sense of Obligation by Henry Maxwell Dempsey (AKA Harry Harrison)

Related Words

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