all of a sudden
Out of nowhere
All of a sudden means unexpectedly, without warning: All of a sudden the lights went out.
The phrase functions identically to suddenly but adds slight dramatic emphasis.
It appears almost exclusively in this fixed form—of a sudden alone sounds archaic, though it once stood on its own.
- unexpectedlyWithout prior indication
- without warningUnexpectedly, lacking prior notice
- unawaresWithout prior knowledge
- abruptlyWithout gradual transition
- in an instantWith no delay
in the blink of an eye · out of nowhere · quick as a flash · wham · in a flash · before you know it · just like that · all at once · plot twist · bolt from the blue · bang · spontaneously · surprise · like a ton of bricks · immediately · caught off guard · startled · burst
- instantlyinstantly, immediately, at once, abruptly, in a flash
- suddennessabrupt, abruptly, instant, instantly, immediate
all of a suddengradually
In slow stages
little by little · slowly · incrementally · bit by bit · over time
all of a suddenpredictably
In an expected manner
as expected · expectedly · unsurprisingly · foreseeably · right on schedule