Opaque

• POS: Adjective, Noun, Verb (usu participle), Verb (transitive)
• HYPHEN: o=paque

CIDE DICTIONARY

Opaque, a. [F., fr. L. opacus. Cf. Opacous.].

•  Impervious to the rays of light; not transparent; as, an opaque substance.  [1913 Webster]
•  Obscure; not clear; unintelligible.  [1913 Webster]

Opaque, n. 

 That which is opaque; opacity.  Young.  [1913 Webster]

OXFORD DICTIONARY

Opaque, adj. & n.
--adj. (opaquer, opaquest)
1 not transmitting light.
2 impenetrable to sight.
3 obscure; not lucid.
4 obtuse, dull-witted.
--n.
1 an opaque thing or substance.
2 a substance for producing opaque areas on negatives.

Derivative

opaquely adv. opaqueness n.

Etymology

ME opak f. L opacus: spelling now assim. to F

THESAURUS

Opaque

Boeotian, abstruse, adiaphanous, ambiguous, amorphous, amphibological, arcane, asinine, backward, baffling, becloud, beef-brained, beef-witted, black, blind, blockish, blurred, blurry, bovine, chumpish, clear as mud, cloddish, cloud, clouded, cloudy, cowish, crass, cryptic, dark, darken, dense, dim, doltish, dull, dull-witted, dullard, dumb, duncical, duncish, dunderheaded, elusive, enigmatic, equivocal, fat, foggy, fuzzy, gross, grumly, hazy, impenetrable, impermeable, impervious to light, indefinite, indeterminate, indistinct, ineducable, intransparent, klutzy, lumpish, misty, muddy, murky, mysterious, mystifying, nebulous, nubilous, oafish, obfuscated, obscure, obscured, obtuse, perplexing, puzzling, recondite, roiled, roily, shadowy, shapeless, slow, smoky, sottish, stolid, stupid, tenebrous, thick, thickheaded, transcendent, turbid, uncertain, unclear, unfathomable, unintelligent, unintelligible, unplain, unteachable, vague, wrongheaded

ROGET THESAURUS

Opaque

Opacity

N opacity, opaqueness, film, cloud, opaque, impervious to light, adiaphanous, dim, turbid, thick, muddy, opacous, obfuscated, fuliginous, cloud, hazy, misty, foggy, vaporous, nubiferous, muggy, smoky, fumid, murky, dirty.

Unintelligibility

N unintelligibility, incomprehensibility, imperspicuity, inconceivableness, vagueness, obscurity, ambiguity, doubtful meaning, uncertainty, perplexity, spinosity, obscurum per obscurius, mystification, latency, transcendentalism, paradox, oxymoron, riddle, enigma, puzzle, diagnus vindice nodus, sealed book, steganography, freemasonry, pons asinorum, asses' bridge, high Dutch, Greek, Hebrew, jargon, unintelligible, unaccountable, undecipherable, undiscoverable, unknowable, unfathomable, incognizable, inexplicable, inscrutable, inapprehensible, incomprehensible, insolvable, insoluble, impenetrable, illegible, as Greek to one, unexplained, paradoxical, enigmatic, enigmatical, puzzling (secret), indecipherable, obscure, dark, muddy, clear as mud, seen through a mist, dim, nebulous, shrouded in mystery, opaque, dense, undiscernible, misty, hidden, latent, indefinite, garbled, perplexed, undetermined, vague, loose, ambiguous, mysterious, mystic, mystical, acroamatic, acroamatical, metempirical, transcendental, occult, recondite, abstruse, crabbed, inconceivable, inconceptible, searchless, above comprehension, beyond comprehension, past comprehension, beyond one's depth, unconceived, inexpressible, undefinable, incommunicable, unpredictable, unforeseeable, it's Greek to me.