# opacity

/oʊˈpæsəti/ (US) · /ɒpˈæsɪti/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/opacity
Updated: 2026-05-20

## Definition

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.

For teachers: 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.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.