12
annoying(adjective, nasty, unpleasant, disgusting, hateful)
12
pernicious(adjective, bad, evil, harmful, injurious)
12
pestilential(adjective, bad, evil, harmful, injurious)
11
pesky(adjective, tough, nasty, offensive, terrible)
11
pestilent(adjective, harmful, dangerous, fatal, poisonous)
10
baneful(adjective, bad, evil, harmful, injurious)
10
bothersome(adjective, annoying)
10
irritating
9
harmful(adjective, bad, injurious, damaging, deadly)
9
noxious(adjective, bad, evil, harmful, injurious)
9
vexatious
8
deleterious(adjective, bad, evil, harmful, injurious)
8
galling
8
noisome(adjective, bad, evil, offensive, immoral)
8
pestering
8
teasing
7
destructive(adjective, bad, harmful, injurious, noxious)
7
nettlesome
7
plaguey
7
toxic(adjective, bad, evil, harmful, injurious)
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APASmart Define. (2015). pestiferous thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/pestiferous/thesaurus/synonyms
ChicagoSmart Define. 2015. "pestiferous thesaurus" https://smartdefine.org/pestiferous/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, pestiferous thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/pestiferous/thesaurus/synonyms>.
MLASmart Define. "pestiferous thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/pestiferous/thesaurus/synonyms>