English Reference
Idiom idiom

at once


to do something immediately or at the same time as something else.


SIMPLE

Please finish your homework at once.

CONTEXTUAL

The fire alarm rang, so everyone left the building at once.

COMPLEX

The king demanded that his advisors address the crisis at once, as the kingdom could not afford any further delay.


From Middle English at ones, equivalent to at + once.

Last updated April 22, 2026