not transparent or translucent; impenetrable to light; not allowing light to pass through.

not transmitting radiation, sound, heat, etc.

not shining or bright; dark; dull.

hard to understand; not clear or lucid; obscure

The problem remains opaque despite explanations.

dull, stupid, or unintelligent.

something that is opaque.

Photography . a coloring matter, usually black or red, used to render part of a negative opaque.

Photography . to cover up blemishes on (a negative), esp. for making a printing plate.

to cause to become opaque.

adjective

clear , lucid , translucent , transparent , unclouded , crystal-clear , easy , unambiguous , understandable

adjective

blurred , cloudy , dark , darkened , dim , dirty , dull , dusky , filmy , foggy , frosty , fuliginous , gloomy , hazy , impenetrable , lusterless , misty , muddied , murky , nontranslucent , nontransparent , nubilous , obfuscated , shady , smoky , sooty , thick , turbidnotes:oblique means slanting or inclined in direction or course or position - or misleading; opaque means not transmitting or reflecting light - or not clearly understood or expressed , abstruse , amphibological , arcane , baffling , concealed , cryptic , difficult , enigmatic , equivocal , imperceptive , incomprehensible , obscure , obtuse , perplexing , purblind , tenebrous , uncertain , unclear , unfathomable , unintelligible , vaguenotes:oblique means slanting or inclined in direction or course or position - or misleading; opaque means not transmitting or reflecting light - or not clearly understood or expressed , (colloq.) obscure , adiaphorous , clouded , dense , impervious , intransparent , muddy , stupid , vague