9
dangerous(adjective, bad, heavy, foul, harmful)
9
injurious(adjective, cruel, unkind, distressing, adverse)
9
detrimental(adjective, bad, evil, cruel, unkind)
9
murderous(adjective, difficult)
9
appalling(adjective, awful, terrible, horrible, afraid)
9
devastating(adjective, bad, evil, destruction, grim)
9
disastrous(adjective, sad, painful, suffering, dreadful)
9
dreadful(adjective, awful, terrible, horrible, afraid)
9
ruinous(adjective, bad, destruction, painful, suffering)
8
bloodthirsty(adjective, murderous)
8
catastrophic(adjective, sad, awful, painful, suffering)
8
ferocious(adjective, awful, terrible, horrible, afraid)
8
implacable
8
savage
8
tedious(adjective, dull, dry, boring, dreary)
8
vicious(adjective, awful, terrible, horrible, afraid)
7
pestilential(adjective, help, bad, evil, harmful)
7
tragic(adjective, bad, awful, terrible, horrible)
7
awful(adjective, terrible, horrible, afraid)
7
calamitous(adjective, sad, painful, suffering, dreadful)
10 years ago|21k views|share |citing 
APASmart Define. (2016). deadly thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/deadly/thesaurus/synonyms
ChicagoSmart Define. 2016. "deadly thesaurus" https://smartdefine.org/deadly/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, deadly thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/deadly/thesaurus/synonyms>.
MLASmart Define. "deadly thesaurus" 26 March 2016. Web. 22 September 2026. <https://smartdefine.org/deadly/thesaurus/synonyms>