- lightless
- adjdark, pitch-dark, dark as night, nightly, nightlike, unlighted, unlit, unilluminated, aphotic, tenebrous, obscure, Literary. darkling; black, black as ink, inky, pitchy, jetblack, nigrescent; ill-lighted, poorly lit, dim, dull, faint, dusky, gloomy, Stygian, shady, shadowy, penumbral, penumbrous, Archaic. caliginous.
A Note on the Style of the synonym finder. 2014.