all of a sudden
adverb
1 all of a sudden
Without warning.
synonym: all at once.
2 all of a sudden
Happening unexpectedly.
synonyms: of a sudden, suddenly.
Moby thesaurus: 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 ... show more.
debug info: 0.0254