source: Ore No Imouto Ga Konna Ni Kawaii Wa Oreimo 2 GIF - Find & Share on GIPHY

adjective (opaquer, opaquest)

not able to be seen through; not transparent:

〈ガラス･液体などが〉不透明な, 曇った, 【光を】通さない «to» (↔ transparent)

e.g. the windows were opaque with steam.

(especially of language) hard or impossible to understand; unfathomable:

〈演説･文章などが〉 «…にとって» 不明瞭な, わかりにくい «to»

e.g. technical jargon that was opaque to her.

an opaque thing or substance.

Photography a substance for producing opaque areas on negatives.

opaquely |ōˈpāklē| adverb

opaqueness |ōˈpāknəs| noun

late Middle English opake, from Latin opacus ‘darkened’. The current spelling (rare before the 19th century) has been influenced by the French form.