sinister

sinister adjective alarming, baleful, baneful, censurable, cold-blooded, comminatory, contemptible, corrupt, creepy, cruel, culpable, dangerous, demoniac, demoniacal, deserving of condemnaaion, designing, despiteful, destructive, detrimental, diabolic, diabolical, dishonest, disingenuous, dismaying, disquieting, disreputable, disturbing, dreadful, eerie, envenomed, evil, exceptionable, facinorous, fear-inspiring, fearsome, fiendish, flagitious, flawed, frightening, ghoulish, harmful, heartless, heinous, horrible, horrid, hurtful, ignoble, ill-disposed, immeritorious, immoral, impious, inauspicious, injurious, inquitous, insidious, intimidating, lawless, malefic, maleficent, maleficial, malevolent, malicious, malign, malignant, menacing, minatory, mischievous, miscreant, murderous, nefarious, nocuous, noisome, noxious, peccable, peccant, pernicious, perverse, portending evil, presageful, rascally, remorseless, reprehensible, satanic, scatheful, scheming, scoundrelly, sinful, spiteful, tainted, terrible, threatening, treacherous, truculent, uncommendable, unfair, unfavorable, unprincipled, unpromising, unpropitious, unrighteous, untrustworthy, unwholesome, venomous, villainous, wicked, worthy of blame, wrong

---

See also: arrant, bad, blameworthy, diabolic, dire, heinous, malevolent, malignant, nefarious, odious, offensive, ominous, onerous, pernicious, portentous, unfavorable, unpropitious