5
dire(adjective, severe, awful, terrible, dreadful)
5
contrary(adjective, damaging, unfavorable, disparaging, hurtful)
5
corrupting(adjective, distressing, injurious, damaging, destructive)
5
devastating(adjective, bad, evil, dreadful, injurious)
5
inexpedient(adjective, damaging, disparaging, hurtful, detrimental)
5
malevolent
5
not helpful
5
ominous(adjective, cruel, unkind, upsetting, threatening)
5
treacherous(adjective, dangerous, injurious, detrimental)
5
vicious
4
abusive(distressing, damaging)
4
foul(adjective, mean, bad, wrong, evil)
4
antagonistic(adjective, person, mean, bad, wrong)
4
brutal(adjective, arouse bad emotions)
4
consumptive(adjective, injurious, damaging, deadly, destructive)
4
corroding(adjective, injurious, damaging, destructive, hurtful)
4
corrupt(immoral, threatening, sinful, injurious, menacing)
4
crippling(adjective, injurious, damaging, destructive, hurtful)
4
insanitary(injurious, detrimental)
4
maleficent
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APASmart Define. (2016). harmful thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/harmful/thesaurus/synonyms
ChicagoSmart Define. 2016. "harmful thesaurus" https://smartdefine.org/harmful/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, harmful thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/harmful/thesaurus/synonyms>.
MLASmart Define. "harmful thesaurus" 24 March 2016. Web. 23 September 2026. <https://smartdefine.org/harmful/thesaurus/synonyms>