all of a sudden
1
in an unexpected or abrupt manner
- All of a sudden, the storm rolled in, darkening the sky.
- He felt dizzy all of a sudden and had to sit down.
- All of a sudden, the dog started barking loudly.
- She burst into laughter all of a sudden, surprising everyone around her.
- All of a sudden, the power went out, leaving the house silent.
2
happening unexpectedly
Synonyms: