a.
1.
Obscure, dark, dim, dusky.
2.
Dismal, cheerless, lowering, lurid.
3.
Sad, dejected, depressed, dispirited, disheartened, despondent, desponding, melancholy, downcast, crestfallen, chapfallen, down-hearted, glum, heavy of heart.
4.
Depressing, dispiriting, saddening, sad, disheartening, melancholy, heavy, dark.