17
poisonous(adjective, harmful, dangerous, deadly, lethal)
16
baneful(adjective, bad, evil, harmful, injurious)
15
terminal(adjective, deadly, final, lethal)
14
baleful(adjective, bad, evil, harmful, injurious)
13
calamitous(adjective, help, painful, suffering, dreadful)
12
fateful(adjective, help, important, decide, critical)
12
harmful(adjective, bad, evil, dreadful, dangerous)
12
virulent(adjective, deadly, poisonous, lethal)
11
cataclysmic(adjective, help, painful, suffering, dreadful)
11
malignant(adjective, dangerous, deadly, diseased, lethal)
10
noxious(adjective, bad, evil, harmful, dangerous)
10
toxic(adjective, bad, evil, harmful, dangerous)
9
dangerous(adjective, hazardous, troubling)
9
deathly(adjective, live, dangerous, deadly, lethal)
9
inevitable(adjective, important, critical, deadly, doomed)
7
foreordained(adjective, important, critical, doomed)
7
damaging(adjective, bad, evil, harmful, dangerous)
7
devastating(adjective, bad, evil, wicked, dreadful)
7
dire(adjective, sad, heavy, painful, suffering)
7
hopeless(adjective, disease, pessimistic, futile)
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APASmart Define. (2016). fatal thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/fatal/thesaurus/synonyms
ChicagoSmart Define. 2016. "fatal thesaurus" https://smartdefine.org/fatal/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, fatal thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/fatal/thesaurus/synonyms>.
MLASmart Define. "fatal thesaurus" 3 April 2016. Web. 20 September 2026. <https://smartdefine.org/fatal/thesaurus/synonyms>