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. opaquely adv. opaqueness n.
[ ME opak f. L opacus: spelling now assim. to F ]