The Collaborative International Dictionary of English v.0.48:
gloomful \gloom"ful\ adj. partially or totally dark. [archaic] Syn: glooming, gloomy. [WordNet 1.5]WordNet (r) 3.0 (2006):
gloomful adj 1: depressingly dark; "the gloomy forest"; "the glooming interior of an old inn"; "`gloomful' is archaic" [syn: glooming, gloomy, gloomful, sulky]