28
toxic(adjective, help, heavy, foul, unhealthy)
25
venomous(adjective, help, mean, bad, nasty)
25
malignant(adjective, mean, bad, evil, nasty)
21
noxious(adjective, mean, bad, nasty, offensive)
21
virulent(adjective, help, mean, bad, nasty)
20
deadly(adjective, bad, offensive, foul, disgusting)
19
lethal(adjective, bad, harmful, dangerous, deadly)
17
pernicious(adjective, mean, bad, evil, nasty)
16
fatal(adjective, harmful, dangerous, deadly, lethal)
16
baneful(adjective, offensive, foul, disgusting, unhealthy)
16
harmful(adjective, bad, evil, offensive, cruel)
15
dangerous(adjective, bad, offensive, violent, wild)
14
baleful(adjective, mean, bad, evil, nasty)
14
deleterious(adjective, mean, bad, evil, nasty)
14
destructive(adjective, bad, cruel, unkind, harmful)
14
nasty(adjective, mean, bad, taste, attitude)
14
vicious(adjective, mean, bad, evil, nasty)
13
injurious(adjective, mean, bad, evil, nasty)
13
malicious(adjective, mean, bad, evil, nasty)
12
bad(adjective, evil, nasty, offensive, violent)
<1234510>
11 years ago|15k views|share |citing 
APASmart Define. (2015). poisonous thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/poisonous/thesaurus/synonyms
ChicagoSmart Define. 2015. "poisonous thesaurus" https://smartdefine.org/poisonous/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, poisonous thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/poisonous/thesaurus/synonyms>.
MLASmart Define. "poisonous thesaurus" 19 August 2015. Web. 22 September 2026. <https://smartdefine.org/poisonous/thesaurus/synonyms>