16
unkind(adjective, person, mean, bad, wrong)
15
unfortunate(adjective, evil, nasty, sad, unhappy)
14
vindictive(adjective, person, evil, nasty, negative)
14
malign(adjective, evil, nasty, dark, negative)
14
malignant(adjective, bad, evil, nasty, negative)
14
baneful(adjective, evil, nasty, negative, malevolent)
14
fiendish(adjective, person, evil, unwarmhearted)
14
villainous(adjective, false, behavior, wicked, deceitful)
13
creepy(adjective, bad, nasty, awful, disgusting)
13
base(adjective, unpleasant, corrupt, wicked, horrible)
12
dishonest(adjective, evil, nasty, false, corrupt)
12
corrupt(adjective, evil, nasty, false, wicked)
12
dismal(adjective, bad, obscure, sad, dark)
12
gloomy(adjective, hard, obscure, rough, nasty)
12
injurious(adjective, bad, evil, nasty, harmful)
12
portentous(adjective, nasty, black, menacing, baleful)
12
unpropitious(adjective, mean, bad, wrong, evil)
11
forbidding(adjective, person, appearance, rough, nasty)
11
minatory(adjective, threatening)
11
unsympathetic(adjective, person, negative, behavior, unwarmhearted)
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APASmart Define. (2016). sinister thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/sinister/thesaurus/synonyms
ChicagoSmart Define. 2016. "sinister thesaurus" https://smartdefine.org/sinister/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, sinister thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/sinister/thesaurus/synonyms>.
MLASmart Define. "sinister thesaurus" 3 April 2016. Web. 22 September 2026. <https://smartdefine.org/sinister/thesaurus/synonyms>