overnight

When something happens overnight, it occurs during the hours of one night. An overnight party can also be called a sleepover or a slumber party. (Pack your sleeping bag, but you probably won't use it.)

You can use overnight as an adverb or adjective literally meaning "during the night" — like an overnight airplane flight or a guest who stays overnight on your couch. You can also use it figuratively, to mean "quickly" or "instant." After you publish your first book, you may be an overnight success; and after an important election, the world may seem to change overnight.

Definitions of overnight
1

adv during or for the length of one night

“the fish marinates overnight

adv happening in a short time or with great speed

“these solutions cannot be found overnight!”

adj lasting, open, or operating through the whole night

“an overnight trip”
Synonyms:
all-night, nightlong
long
primarily temporal sense; being or indicating a relatively great or greater than average duration or passage of time or a duration as specified

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