Synonyms of catastrophic

2 Syllables
fatal, wreckful, ruinous, harmful, woeful, tragic
3 Syllables
tumbledown, hellfire, ill-fated, ill-starred, star-crossed, unlucky, disastrous
4 Syllables
lethiferous, cataclysmic, cataclysmal, destructive, calamitous, catastrophal
5 Syllables
extirpative, fire-and-brimstone, misfortunate
6 Syllables
annihilative, eradicative