87 entries under harmful topic. ×

13
prejudicial(adjective, bad, cruel, unkind)
13
malevolent(adjective, mean, bad, evil, nasty)
13
pestilent(adjective, help, bad, unhealthy)
12
dangerous(adjective, bad, offensive, foul, disgusting)
11
malign(adjective, mean, bad, evil, nasty)
11
pestilential(adjective, help, bad, evil)
11
sinister(adjective, bad, evil, nasty, negative)
10
mischievous(adjective, mean, bad, nasty, cruel)
10
pestiferous(adjective, bad, evil, injurious)
10
wicked(adjective, mean, bad, evil, nasty)
9
nocuous(adjective, cruel, unkind, distressing)
9
venomous(adjective, mean, bad, evil, nasty)
8
noisome(adjective, bad, evil, offensive, immoral)
8
unwholesome(adjective, offensive, foul, disgusting, unhealthy)
7
mortal(adjective, bad, evil, grave)
7
vicious(adjective, mean, bad, evil, nasty)
6
devastating(adjective, bad, evil, wicked, dreadful)
6
disastrous(adjective, bad, wicked, immoral, dreadful)
5
calamitous(adjective, bad, wicked, immoral, dreadful)
5
insalubrious(adjective, offensive, foul, disgusting)
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APASmart Define. (2016). pernicious thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/pernicious/thesaurus/synonyms
ChicagoSmart Define. 2016. "pernicious thesaurus" https://smartdefine.org/pernicious/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, pernicious thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/pernicious/thesaurus/synonyms>.
MLASmart Define. "pernicious thesaurus" 24 March 2016. Web. 26 September 2026. <https://smartdefine.org/pernicious/thesaurus/synonyms>