Synonyms of deleterious

1 Syllable

bad

2 Syllables

deadliest, deadlier, wreckful, septic, ruining, ruinous, harmful, noxious, destroying, nocent, nocuous, maligns, deadly, malign, dickens, hurtful

3 Syllables

pernicious, malefic, injurious, mischievous, malicious, debit-side, tumbledown, toxicant, damaging, blackhearted, rascally, poisonous, pestilent, noisome, baneful, sinister, miasmatic, praetorian, maligning

4 Syllables

lethiferous, insalubrious, ill-behaved, prejudicial, dyslogistic, detrimental, unnutritious, maleficent, destructive, mephitical, prejudicious

5 Syllables

extirpative, disadvantageous, unconducive, insalutary, unwholesome

6 Syllables

counterproductive, annihilative, eradicative, degenerative