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.

Definitions of opacity
  1. noun
    the quality of being opaque to a degree; the degree to which something reduces the passage of light
    synonyms: opaqueness
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    clarity, clearness, uncloudedness
    the quality of clear water
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    cloudiness, muddiness, murkiness
    the quality of being cloudy
    blurriness, fogginess, fuzziness, indistinctness, softness
    the quality of being indistinct and without sharp outlines
    turbidity, turbidness
    muddiness created by stirring up sediment or having foreign particles suspended
    haziness, mistiness, steaminess, vaporousness, vapourousness
    cloudiness resulting from haze or mist or vapor
    dimness, faintness
    the quality of being dim or lacking contrast
    indistinctness of shape or character
    type of:
    an essential and distinguishing attribute of something or someone
  2. noun
    the phenomenon of not permitting the passage of electromagnetic radiation
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    transparence, transparency
    permitting the free passage of electromagnetic radiation
    optical opacity
    opacity to light
    radio-opacity, radiopacity
    opacity to X-rays or other radiation
    type of:
    physical phenomenon
    a natural phenomenon involving the physical properties of matter and energy
  3. noun
    incomprehensibility resulting from obscurity of meaning
    synonyms: opaqueness
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    type of:
    the quality of being incomprehensible
DISCLAIMER: These example sentences appear in various news sources and books to reflect the usage of the word ‘opacity'. Views expressed in the examples do not represent the opinion of or its editors. Send us feedback
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