I. (ˈ)ō|pāk adjective
( sometimes -er/-est )
Etymology: alteration (influenced by French opaque ) of earlier opake, from Latin opacus shaded, dark, perhaps from op-, ob to, before — more at epi-
1. archaic : lacking illumination
2. : neither reflecting nor emitting light — not in current technical use
3.
a. : impervious to the rays of visible light : not transparent or translucent
his eyes were light, large, and bright, but it was that kind of brightness which belongs to an opaque , and not to a transparent body — Anthony Trollope
b. : impervious to forms of radiant energy other than visible light (as infrared radiation or radio waves)
organic compounds containing iodine or bromine are also opaque to roentgen rays — C.H.Thienes
4.
a. : hard to understand, solve, or explain : not simple, clear, or lucid
how opaque and incredible the past seems to us — L.P.Smith
b. : impervious to reason : stupid , dull , dense
too opaque to recognize the insult
Synonyms: see dark
II. noun
( -s )
: something that is opaque : an opaque medium or space: as
a. : an opaque paint or other preparation for blocking out portions of a photographic negative or print
b. : an opaque photographic print — contrasted with transparency
III. transitive verb
( -ed/-ing/-s )
1. : to make opaque
2. : to apply opaque to (as parts of a photographic negative or positive)