Synonyms for Dark:

adj.

angry, upset (adjective)
sulky, frowning, sullen, scowling, glowering, glum, dour.
black (adjective)
midnight, sable, dingy, charcoal, ebony, black.
dark (adjective)
dreary, dusky, darkened, lightless, inky, gloomy, sooty, murky, silhouetted, somber, dim, swarthy, black, dismal, shady, cloudy, shadowy, umbrageous, obscure, shaded.
darkish (adjective)
dim.
dim (adjective)
misty, lightless, unilluminated.
dirty (adjective)
sooty.
dull (adjective)
hazy, unlit.
evil (adjective)
corrupt, immoral, iniquitous.
evil, satanic (adjective)
corrupt, immoral, wicked.
grim, hopeless (adjective)
sinister, dismal, unpropitious, morose, foreboding, joyless, cheerless.
hidden, secret (adjective)
concealed, cryptic, deep.
ignorant (adjective)
unenlightened, benighted, ignorant, uncultivated.
incomprehensible (adjective)
impenetrable.
invisible (adjective)
covert, imperceptible, invisible, concealed, indiscernible, camouflaged, unapparent, Obscured, hidden, latent, unobservable.
lack of light (adjective)
black, caliginous, nebulous, dingy, murky, cloudy, dusky, vague, dim, pitchy, gloomy, indistinct, somber, crepuscular, unlit, shadowy, dusk, opaque, sunless, unlighted, pitch-dark, clouded, darkened, foggy, faint, misty, sooty, lightless, shady, stygian, blackish, aphotic, shaded, overcast, obscure, cimmerian, inky, dull, tenebrous.
night (adjective)
nighttime, twilight, eventide, evening, night, dusk.
opaque (adjective)
murky, opaque, unclear, cloudy, vague, impenetrable, hazy, obscure.
overcast (adjective)
overcast.
shaded complexion, hair (adjective)
swarthy, brunette, dark-skinned, sable, ebony, brunet, bistered, tan.
sullen (adjective)
broody, contrary, mean, fretful, malevolent, cynical, glowering, ungenial, dour, petulant, grouchy, grumpy, sullen, dejected, noncooperative, sour, gloomy, moody, unfriendly, Moping, obstinate, cross, dissociable, grim, glum, long-faced, surly, irascible, sulky, uncooperative, cantankerous, beetle-browed, scowling, morose, melancholy, crabby, hostile, frowning, unsociable.
tenebrific (adjective)
tenebrific, broody.
ulterior (adjective)
Obscured.
unenlightened (adjective)
benighted.

n.

in, opposite, go up, on, rep, method acting, acting, cryptic, secret, dramatic. unpropitious, painful, terrible, unhappy, tragic, heartbreaking, foreboding, upsetting. amber, avocado, beige, alabaster, azure, african, negro, baby blue, amethyst, indian, tan. sordid, amoral, perverted, deviant, gross. uncertain, anonymous, strange, personal, private. fatalistic, negative, colors, broken, despairing, blackish. Black-a-vised, bistered, Flaxen, fair-haired, blond, fair, auburn. Lowery, Complexioned, bloodless, bronzed, warn, brown, Complected, albino, color. hope, pessimistic. obscureness, dimness, obscurity, murkiness. dark (noun)
pitch-dark, caliginous, saturnine, dour, incomprehensible, acherontic, tenebrific, darkening, unlit, inactive, wicked, darkness, tenebrious, colored, tenebrous, lightproof, nighttime, glum, obscure, gloomy, moody, grim, glowering, stygian, gloomful, darkened, morose, benighted, black, ill-natured, evil, cheerless, acheronian, night, glooming, twilight, blue, cimmerian, coloured, concealed, iniquity, wickedness, dim, uncomprehensible, dusky, brunette, dark-skinned, sour, twilit, disconsolate, lightless, sullen, crepuscular, uncheerful, darkish, light-tight, unenlightened, brunet, dispiriting, depressing, unilluminated, shadow, darkling, sinister, subdued, aphotic, unlighted, dismal.
darkness (noun)
shadow, dimness, the dark, shade, gloom, murk, blackness.
dismal (noun)
hopeless.
night (noun)
sundown, sunset, vesper.
place, time without light (noun)
evening, obscurity, shade, nighttime, murkiness, gloom, night, twilight, murk, darkness, dimness, midnight.
state (noun)
darkness, wickedness.

Other synonyms:

Acherontic
acherontic.
joyless, absent, rep, desolate. fair, go up, pessimistic. in, on. Stygian
stygian.
cloudy
overcast, sunless.
indistinct
nebulous.
shadowy
pitchy.
Other relevant words:
overcast, blackish, uncertain, darkness, cheerless, darkling, sinister, faint, secret, indistinct, dull, clouded, benighted, darkish.

Usage examples for dark

  1. Why is it so dark in there? – Dr. Adriaan by Louis Couperus
  2. Dark day, isn't it? – The Iron Woman by Margaret Deland
  3. And neither could have gone very far in the dark – The Enchanted Canyon by Honoré Willsie Morrow