1. (superl.) Imperfectly illuminated; dismal through obscurity or darkness; dusky; dim; clouded; as, the cavern was gloomy.

2. (superl.) Affected with, or expressing, gloom; melancholy; dejected; as, a gloomy temper or countenance.

Acheronian Acherontic Cassandra-like Cassandran Cassandrian Cimmerian Stygian acheronian acherontic apocalyptic bad baleful baneful black bleak blue bodeful boding caliginous castellatus cheerless cirrose cirrous cloud-flecked clouded cloudy cold crabbed crestfallen cumuliform cumulous cynical dark dark and gloomy defeatist dejected depressant depressed depressing depressive desolate despairing despondent dim dire dirty disconsolate discouraging disheartening dismal dispirited dispiriting distressed doleful doomful dour down downbeat downcast downhearted drab drear drearisome dreary dull dun dusky evil evil-starred fateful foreboding forlorn funebrial funereal gloomful glooming glum grave gray grim heavy ill ill-boding ill-fated ill-lighted ill-lit ill-omened ill-starred in the doldrums inauspicious inky joyless lenticularis lowering lugubrious mammatus melancholy menacing mirthless miserable moody morose murky muzzy nebulous negative negativistic nihilistic nimbose nubilous obscure of evil portent ominous oppressed oppressive overcast overclouded pessimist pessimistic portending portentous sad saturnine shaded shadowy shady sinister solemn somber sombrous sorrowful squally stormy stratiform stratous sulky sullen surly tenebrous threatening thunderheaded triste ugly uncheerful unfavorable unfortunate unhappy unilluminated unlucky unpromising unpropitious untoward weariful wearisome weary woebegone