adjective
harmful
Synonyms: bad, baleful, baneful, corrupt, corruptive, dangerous, deadly, deleterious, destructive, detrimental, evil, fatal, hurtful, infective, lethal, malicious, malignant, mephitic, miasmatic, morbid, mortal, nocuous, noisome, noxious, peccant, pernicious, pestiferous, pestilential, poison, septic, toxic, toxicant, toxiferous, venomous, vicious, viperous, virulent
Antonyms: benevolent, harmless, non-toxic
adjective
harmful
Synonyms: bad, baleful, baneful, corrupt, corruptive, dangerous, deadly, deleterious, destructive, detrimental, evil, fatal, hurtful, infective, lethal, malicious, malignant, mephitic, miasmatic, morbid, mortal, nocuous, noisome, noxious, peccant, pernicious, pestiferous, pestilential, septic, toxic, toxicant, toxiferous, venomous, vicious, viperous, virulent
Antonyms: aiding, antidotal, assisting, curing, healing, helpful