Synonyms of toxic

2 Syllables
deadliest, deadlier, wreckful, septic, harmful, noxious, lethal, miasmic, poison, deadly
3 Syllables
pernicious, mephitic, unhealthful, viperish, infectious, toxicant, venomous, poisonous, baneful, miasmatic, virulent
4 Syllables
lethiferous, insalubrious, pestilential, pestiferous, unnutritious, uneatable, destructive, transmittable, infective, mephitical
5 Syllables
extirpative, unwholesome, indigestible
6 Syllables
eradicative