say it: oh-PAYK
opaque is an adjective meaning "not transmitting or reflecting light or radiant energy; impenetrable to sight". It carries 2 recorded senses.
not transmitting or reflecting light or radiant energy; impenetrable to sight
“opaque windows of the jail”
“opaque to X-rays”
hard or impossible to understand
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for opaque come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.