10
adverse(adjective, evil, nasty, harmful, injurious)
10
angry(adjective, state, characteristic, person, unpleasant)
10
antagonistic(adjective, person, malevolent, unwarmhearted)
10
hard(adjective, person, sad, unhappy, unpleasant)
10
hateful(adjective, person, mean, bad, wrong)
10
lurid(adjective, bad, sorrow, awful, depress)
10
spooky(adjective, bad, awful, disgusting, black)
9
dour(adjective, person, rough, nasty, dark)
9
eerie(adjective, bad, sorrow, awful, depress)
9
fateful(adjective, black, warning, threatening, menacing)
9
harmful(adjective, bad, evil, nasty, injurious)
9
ill-boding(adjective, nasty, black, threatening, menacing)
9
ill-fated(adjective, person, sad, unhappy, unpleasant)
9
inhumane(adjective, person, evil, negative, behavior)
9
lowering(adjective, nasty, sorrow, depress, sadness)
9
minacious
9
sinful(adjective, evil, wicked, injurious, damaging)
9
unfavorable(adjective, evil, nasty, threatening, menacing)
9
unfavourable(adjective, ominous)
9
unfriendly(adjective, person, evil, negative, 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>