English Reference

Word

opacity

Phoneticsopac·i·ty

US/oʊˈpæsəti/

UK/ɒpˈæsɪti/

Definition

n. the quality of being hard to see through. You use this to describe things like thick fog, dark glass, or even a secret that is hard to understand.

n. the degree to which a substance or surface prevents the passage of light or other forms of radiation. In a figurative sense, it refers to the quality of being difficult to understand or explain.

Examples

“The new software update increased the opacity of the background, making the text much easier to read.”

“The committee's refusal to release the full report created a sense of opacity that led to public suspicion and a loss of trust in the organization.”

Examples

contextual

“The new software update increased the opacity of the background, making the text much easier to read.”

complex

“The committee's refusal to release the full report created a sense of opacity that led to public suspicion and a loss of trust in the organization.”

Real-World Examples

“The coatings are exceptionally light, with high opacity and brightness achieved by just a single layer of silicon nanospheres.”
Phys.org · 12 Sept 2026
“White packaging, films, and coatings often depend on titanium dioxide (TiO 2 ), which provides both brightness and opacity.”
ScienceDaily · 10 Sept 2026

Etymology

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

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

opacityNounopaqueAdjective

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

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English Reference