opacity

American  

[oh-pas-i-tee] / oʊˈpæs ɪ ti /

noun

• opacities
  plural

1. the state or quality of being opaque.

2. something opaque.

3. the degree to which a substance is opaque; capacity for being opaque.

4. Photography. the proportion of the light that is absorbed by the emulsion on any given area of a film or plate.

5. obscurity of meaning.

6. mental dullness.

7. Medicine/Medical. an opaque spot or area in normally clear or transparent tissue, as a cataract of the eye.

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opacity British  

/ əʊˈpæsɪtɪ /

noun

1. the state or quality of being opaque

2. the degree to which something is opaque

3. an opaque object or substance

4. obscurity of meaning; unintelligibility

5. physics photog the ratio of the intensity of light incident on a medium, such as a photographic film, to that transmitted through the medium

6. logic philosophy the property of being an opaque context

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Other Word Forms

Derived Forms

• nonopacity
  noun

Inflected Forms

Nouns

• opacities
  plural

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Etymology

Origin of opacity

First recorded in 1550–60, opacity is from the Latin word opācitās shade. See opaque, -ity

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Explanation

Opacity is the characteristic of being difficult to understand or unclear. A professor whose lectures are known for opacity is going to find himself in a room full of some very frustrated students. In its literal sense opacity is used to talk about objects that don't allow light to shine through. A window that has accumulated a lot of dirt and dust is characterized by its opacity, as opposed to a transparent window, which is one you can see right through. The word opacity is used more generally for anything obscure, unclear, or incomprehensible, like the opacity of a novel full of ten-syllable words or a dictionary that doesn't give you any clear or straightforward definitions.

Example Sentences

See Examples For:

opacity opacities

The US firm said earlier this year that investors had raised concerns about "ongoing opacity in shareholding structures" as well as co-ordinated trading behaviour that affected price information.

From Barron's ● Oct. 16, 2026

Such opacity makes the ships difficult to police.

From Los Angeles Times ● Oct. 9, 2026

Some analysts, however, argue that opacity in decision-making creates more uncertainty for markets.

From Barron's ● Jul. 26, 2026

But if it’s part of a larger pattern of opacity, instability and conflicting messaging, something larger might be coming down the pike.

From MarketWatch ● Jun. 12, 2026

The opacity and complexity of the bond market was, for big Wall Street firms, a huge advantage.

From "The Big Short" by Michael Lewis

When Sovannarie was 3 months old, her parents noticed something unusual about their daughter: white opacities in both pupils.

From Salon ● Dec. 11, 2022

I think that’s what’s super fun about it: You can create so much depth in a nail from different opacities of color, where you can’t get that with a flat paint.

From Los Angeles Times ● Oct. 13, 2021

The panels come in different opacities — some are clear, while others block more UV light for sun protection.

From Seattle Times ● Mar. 25, 2021

“Don’t Believe a Word,” a new book by the Guardian writer and editor David Shariatmadari, delves into the riddles of language: the opacities, ambushes, dead ends, sudden ecstasies.

From New York Times ● Jan. 1, 2020

But in all these writers cataracta seems to be included under the general term pannus, meaning opacities of every kind.

From Gilbertus Anglicus Medicine of the Thirteenth Century by Henry Ebenezer Handerson

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