opac·​i·​ty | \ ō-ˈpa-sə-tē How to pronounce opacity (audio) \
plural opacities

Definition of opacity

1a : obscurity of sense : unintelligibility
b : the quality or state of being mentally obtuse : dullness
2 : the quality or state of a body that makes it impervious to the rays of light broadly : the relative capacity of matter to obstruct the transmission of radiant energy
3 : an opaque spot in a normally transparent structure (such as the lens of the eye)

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Examples of opacity in a Sentence

the opacity of the glass Critics have noted the opacity of her writing style.
Recent Examples on the Web Such opacity helped to worsen the 2008 financial crisis and regulators have introduced a vast new body of rules governing the assets since then. Fortune, "A massive bet on highly secretive derivatives may have sunk Archegos hedge fund," 29 Mar. 2021 The opacity of other people, the difficulty of making definitive judgments about them, is another Murakami concern. BostonGlobe.com, "For Murakami, a return to form in ‘First Person Singular,’ a new story collection that sparkles," 1 Apr. 2021 Prime brokers at investment banks lent large amounts of money to the firm on margin, perhaps mismeasuring the fund’s risk because of the opacity around derivatives. Daniel Tenreiro, National Review, "The Unwinding of Bill Hwang’s Archegos Has Few Systemic Implications," 30 Mar. 2021 Here, the opacity presents a conundrum: Did Roenne knowingly pass on false information? Sigrid Macrae, Harper's Magazine, "Two Germanys," 16 Mar. 2021 But Israel's strategy of opacity also draws criticism from opponents. Jon Gambrell, Star Tribune, "Secretive Israeli nuclear facility undergoes major project," 25 Feb. 2021 Four jurisdictions have also banned police from signing nondisclosure agreements with surveillance vendors, taking away a common excuse for police opacity. Albert Fox Cahn, Wired, "New York City’s Surveillance Battle Offers National Lessons," 12 Feb. 2021 An artist whose craft depended on his ability to call upon resources from a deep reservoir of feeling, on a certain sense of transparency, left us on a note of opacity that seems to me a final refusal of capture. Reginald Dwayne Betts Kiese Makeba Laymon Carina Del Valle Schorske Dessa Irina Aleksander Sam Dolnick Mark Binelli Maggie Jones Rob Hoerburger Jamie Lauren Keiles Devin Gordon Jazmine Hughes Jenna Wortham Jade Chang Taffy Brodesser-akner Kaitlyn Greenidge Rowan Ricardo Phillips Michael Paterniti Wesley Morris Ismail Muhammad Anthony Giardina, New York Times, "Remembering some of the artists, innovators and thinkers we lost in the past year.," 23 Dec. 2020 There’s an interesting opacity to Claire’s motivations. Doreen St. Félix, The New Yorker, "“A Teacher”: A Series Best Saved for Fourth-Period Health Class," 7 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'opacity.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of opacity

1575, in the meaning defined at sense 1a

History and Etymology for opacity

Middle French opacité shadiness, from Latin opacitat-, opacitas, from opacus shaded, dark

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Time Traveler for opacity

Time Traveler

The first known use of opacity was in 1575

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Statistics for opacity

Last Updated

25 Apr 2021

Cite this Entry

“Opacity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/opacity. Accessed 7 May. 2021.

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More Definitions for opacity



English Language Learners Definition of opacity

: the quality of a material that does not allow light to pass through it : the quality of being opaque
formal : the quality of being difficult to understand or explain


opac·​i·​ty | \ ō-ˈpas-ət-ē How to pronounce opacity (audio) \
plural opacities

Medical Definition of opacity

1 : the quality or state of a body that makes it impervious to the rays of light broadly : the relative capacity of matter to obstruct by absorption or reflection the transmission of radiant energy (as X-rays, infrared radiation, or sound)
2 : an opaque spot in a normally transparent structure (as the lens of the eye)

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