disastrous 0 antonyms and opposites of disastrous. Adj — Causing great damage or harm; having the nature of a disaster. Synonyms for disastrous apocalyptic calamitous cataclysmal cataclysmic catastrophic deadly debacular devastating destructive disadventurous eradicative extirpative fatal harmful lethal pernicious ruinous woeful ← Back to the full definition of disastrous
