List of sinister synonyms and sinister related words.
adverse, amoral, antagonistic, apocalyptic, backhand, backhanded, bad, baleful, baneful, base, black, bodeful, boding, circuitous, conflicting, conscienceless, contrary, corrupt, corrupted, counter, counteractive, counterclockwise, criminal, crooked, dark, deflectional, detrimental, deviant, deviative, devious, diabolical, difficult, digressive, dire, disastrous, dishonest, dishonorable, divagational, divergent, doomful, doubtful, dreary, dubious, evasive, evil, evil-starred, excursive, fateful, felonious, fishy, foreboding, fraudulent, furtive, gloomy, hard, harmful, hostile, ill, ill-boding, ill-fated, ill-got, ill-gotten, ill-omened, ill-starred, immoral, improper, in opposition, inaccurate, inauspicious, indirect, inexpedient, inferior, inimical, insidious, invalid, larboard, left, left-hand, left-handed, left-wing, left-wingish, levorotatory, liberal, lowering, malefic, maleficent, malevolent, malicious, malign, malignant, menacing, minacious, minatory, miserable, near, nefarious, nigh, not easy, not kosher, oblique, of evil portent, ominous, opposed, opposing, opposite, peccant, pernicious, port, portending, portentous, questionable, radical, rigorous, rotten, shady, shameless, shifty, side, sidelong, sinful, sinistral, sinistrocerebral, sinistrocular, sinistrogyrate, sinistrorse, slippery, sneaky, somber, stressful, suspicious, threatening, treacherous, tricky, troublesome, troublous, trying, unconscienced, unconscientious, unconscionable, underhand, underhanded, unethical, unfavorable, unfortunate, unhealthy, unkind, unlucky, unpleasant, unprincipled, unpromising, unpropitious, unsavory, unscrupulous, unskillful, unstraightforward, untoward, vicious, villainous, wicked, without remorse, without shame, wretched, wrong