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)

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 Their constant, roving patrol, their opacity and ubiquity, their bland and cutesy sameness, their programmatic logic seemed to presage a future without privacy or mystery. Anna Wiener, The New Yorker, 20 July 2022 China takes it to the extreme, tapping nationwide reservoirs of data that allow the police to operate with opacity and impunity. New York Times, 25 June 2022 For the average shopper, this opacity can magnify the sense that a particular style has become inescapable overnight, largely unbidden. Amanda Mull, The Atlantic, 23 June 2022 Only the shadows cast by objects will appear, so opacity, size, and shape are key. Kim Hutchison, Better Homes & Gardens, 13 July 2022 At the same time, some of them have come under fire for loose security, financial opacity, and lack of clarity on their corporate structure. Wired, 6 July 2022 The problem is China’s extreme opacity, which in many ways grew worse in Xi’s watch. William Pesek, Forbes, 28 June 2022 Then, like suddenly noticing one can’t see the road ahead, the ensemble shifts almost imperceptibly into opacity, all dense clusters and husky sul ponticello bowings in the strings. Hannah Edgar, Chicago Tribune, 24 May 2022 For all the concerns about the opacity of TikTok’s policies, Stamos and Krapyva both acknowledged that Russia’s actions had left social media platforms with few good options. Washington Post, 13 Apr. 2022 See More

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.

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

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The first known use of opacity was in 1575

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Last Updated

30 Jul 2022

Cite this Entry

“Opacity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/opacity. Accessed 11 Aug. 2022.

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More Definitions for opacity


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)

More from Merriam-Webster on opacity

Nglish: Translation of opacity for Spanish Speakers

Britannica English: Translation of opacity for Arabic Speakers

Britannica.com: Encyclopedia article about opacity


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