Answer: earthshattering

AnswerCrossword Clue
EARTHSHATTERING

Awfully bad

EARTHSHATTERING

Likely to change everything

EARTHSHATTERING

Momentous

EARTHSHATTERING
Of great importance
EARTHSHATTERING
Monumental
EARTHSHATTERINGOf global significance
EARTHSHATTERINGShocking, and then some