aphoticadj.

aphotic (adj.)"untouched by sunlight, lightless" (in reference to deep-sea regions), 1903, Modern Latin, from Greek a- "not, without" (see a- (3)) + phos (genitive photos) "light," related to phainein "to show, to bring to light" (see phantasm) + -ic. Aphotic zone is recorded from 1913.