frequently_asked_questions_files/Oxford Thesaurus.pdf

impermeability, impenetrability: The opacity of the lens
increases automatically in the presence of sunlight. 2
obscurity, density, impenetrability, unintelligibility,
indefiniteness, vagueness, reconditeness, abstruseness,
ambiguity, equivocation, mystification: For centuries
scientists were unable to penetrate the opacity of the question
of what occurred when substances burned. 3 stupidity, dullness,
denseness, thickness, obtuseness: A light finally dawned
through the thick opacity of his brain.
opalescent
adj. opaline, iridescent, nacreous, pearly, lustrous: The sea
was opalescent in the moonlight.
opaque adj. 1 dark, murky, dim, turbid, muddy, cloudy, obscure,
obscured, obfuscated, black, impermeable, impenetrable, clouded,
non-transparent, untransparent, non-translucent, hazy, blurred,
blurry, smoky: Solar eclipses should be viewed directly only
through special opaque glass. 2 unclear, vague, indefinite,
obscure, unfathomable, unplumbable, baffling, mystifying,
ambiguous, equivocal, impenetrable, cryptic, enigmatic,
puzzling, perplexing, mysterious, elusive, abstruse, arcane,
recondite: Despite years of study, the inscriptions on the tomb
have remained opaque to scholars. 3 unintelligent, dense, thick,
dull, obtuse, stupid, dull-witted, stolid, thickheaded,
dunderheaded, dunderpated, slow, doltish, backward, cloddish:
He was too opaque to notice the jeers of his colleagues.
open adj. 1 ajar, gaping, agape, unfastened, unlocked, unbarred,
unbolted, unlatched, unclosed: Come on in - the door is open.
2 yawning, agape, uncovered, revealed, unsealed, exposed, bare:
Her uncle escaped by hiding for three nights in an open grave.
3 unwrapped, unsealed, unfastened: The package was open and the
contents gone. 4 free, accessible, public, available;
obtainable; unrestricted, unobstructed, unencumbered or
unincumbered, unimpeded, unhindered, unhampered, unregulated,
unconditional, unqualified: The parks are open to all. We were
allowed open access to the library stacks. 5 unprotected,
unenclosed, unsheltered, bare; uncovered, exposed: They spent a
week in an open boat before being rescued. The roof can be
retracted, leaving the interior completely open to the sky. 6
unsettled, unagreed, unsigned, unsealed, unclinched,
unestablished, unconcluded, undecided, pending: As far as I am