adjective
injurious, devastating
Synonyms: annihilative, baleful, baneful, calamitous, cancerous, cataclysmic, catastrophic, consumptive, cutthroat, damaging, deadly, deleterious, detrimental, dire, disastrous, eradicative, evil, extirpative, fatal, fell, harmful, hurtful, internecine, lethal, lethiferous, mortal, noisome, noxious, pernicious, pestiferous, pestilential, ruinous, slaughterous, suicidal, toxic, venomous, wrackful, wreckful
Antonyms: aiding, assisting, building, creative, helpful, productive
adjective
hurtful, disparaging
Synonyms: abrasive, adverse, antagonistic, cankerous, caustic, contrary, corrosive, deleterious, derogatory, detrimental, discouraging, discrediting, erosive, hostile, injurious, invalidating, negative, offensive, opposed, troublesome, undermining, vicious
Antonyms: encouraging, hopeful, positive