Opacity

//oʊˈpæsɪti// noun

noun ·Moderate ·College level

Definitions

Noun
  1. 1
    The state or quality of being opaque, not allowing light to pass through. uncountable

    "We could not see the sandbar due to the opacity of the muddy water."

  2. 2
    the quality of being opaque to a degree; the degree to which something reduces the passage of light wordnet
  3. 3
    The state or quality of being inaccessible to understanding. uncountable

    "The opacity of these decisions is troubling."

  4. 4
    incomprehensibility resulting from obscurity of meaning wordnet
  5. 5
    A measure of relative impenetrability to electromagnetic radiation such as light. countable

    "The opacity of a clean glass window is near zero."

Show 2 more definitions
  1. 6
    the phenomenon of not permitting the passage of electromagnetic radiation wordnet
  2. 7
    An opaque area. countable

    "This report concerns a child with Down's syndrome (mongolism) and bilateral congenital corneal opacities born into a family affected through three generations by Rieger's anomaly."

Synonyms

All synonyms
opaquenessopaquenessabstrusenessadiaphanousnessambiguityamorphousness

Example

More examples

"The opacity of the glass made it unsuitable for windowpanes."

Etymology

From opaque + -ity, from French opacité, from Latin opacitas.

Related phrases

referential opacitysnowball opacity

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.