100 entries under harmful topic. ×

12
malignant(adjective, help, mean, bad, evil)
11
lethal(adjective, bad, evil, dangerous)
11
pestilential(adjective, help, bad, evil, foul)
11
putrid(adjective, rank, foul, disgusting, disagreeable)
10
mischievous(adjective, mean, bad, nasty, offensive)
10
venomous(adjective, mean, bad, evil, nasty)
9
corrupting(adjective, immoral, distressing, injurious)
9
fatal(adjective, bad, evil, dangerous)
9
malign(adjective, mean, bad, evil, nasty)
9
ruinous(adjective, mean, bad, wrong, evil)
9
vicious(adjective, mean, bad, evil, nasty)
8
pestiferous(adjective, bad, evil, injurious)
8
prejudicial(adjective, cruel, unkind, distressing, upsetting)
8
stinking(adjective, bad, evil, offensive, base)
6
corrupt(adjective, bad, evil, base, foul)
6
nocuous(adjective, cruel, unkind, distressing, upsetting)
6
suicidal(adjective, violent, cruel, injurious)
6
unhygienic(adjective, dirty, unhealthy, polluted)
6
unsanitary(adjective, dirty, unhealthy, polluted)
6
wicked(adjective, mean, bad, wrong, evil)
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APASmart Define. (2015). noxious thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/noxious/thesaurus/synonyms
ChicagoSmart Define. 2015. "noxious thesaurus" https://smartdefine.org/noxious/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, noxious thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/noxious/thesaurus/synonyms>.
MLASmart Define. "noxious thesaurus" 17 July 2015. Web. 24 September 2026. <https://smartdefine.org/noxious/thesaurus/synonyms>