all of a sudden

THESAURUS

all of a sudden

abruptly, bang, dash, hastily, impetuously, impulsively, like a flash, like a thunderbolt, of a sudden, on short notice, plop, plump, plunk, pop, precipitantly, precipitately, precipitously, sharp, short, slap, smack, startlingly, sudden, suddenly, surprisingly, unawares, unexpectedly, without notice, without warning