n. 25B6; adjective
a dark night : BLACK, pitch-black, jet-black, inky; unlit, unilluminated; starless, moonless; dingy, gloomy, dusky, shadowy, shady; poetic/literary Stygian.
a dark secret : MYSTERIOUS, secret, hidden, concealed, veiled, covert, clandestine; enigmatic, arcane, esoteric, obscure, abstruse, impenetrable, incomprehensible, cryptic.
dark hair : BRUNETTE, dark brown, chestnut, sable, jet-black, ebony.
dark skin : SWARTHY, dusky, olive, black, ebony; tanned, bronzed.
dark days : TRAGIC, disastrous, calamitous, catastrophic, cataclysmic; dire, awful, terrible, dreadful, horrible, horrendous, atrocious, nightmarish, harrowing; wretched, woeful.
dark thoughts : GLOOMY, dismal, pessimistic, negative, downbeat, bleak, grim, fatalistic, black, sombre; despairing, despondent, hopeless, cheerless, melancholy, glum, grave, morose, mournful, doleful.
a dark look : MOODY, brooding, sullen, dour, scowling, glowering, angry, forbidding, threatening, ominous.
dark deeds : EVIL, wicked, sinful, immoral, bad, iniquitous, ungodly, unholy, base; vile, unspeakable, foul, monstrous, shocking, atrocious, abominable, hateful, despicable, odious, horrible, heinous, execrable, diabolical, fiendish, murderous, barbarous, black; sordid, degenerate, depraved; dishonourable, dishonest, unscrupulous; informal low-down, dirty, crooked, shady.
bright, blonde, pale, happy, good.
25B6; noun
he's afraid of the dark : DARKNESS, blackness, gloom, murkiness, shadow, shade; dusk, twilight, gloaming.
she went out after dark : NIGHT, night-time, darkness; nightfall, evening, twilight, sunset.
light, day.
25A0; in the dark (informal) UNAWARE, ignorant, oblivious, uninformed, unenlightened, unacquainted, unconversant.