overnighto·ver·night1 /ˌəʊvəˈnaɪt◂ˌoʊvər-/ adjectiveadj [only before a noun]1done in one nightMuch of what is shipped via overnight express delivery is not really needed the next day.
2continuing for all or most of the nightan overnight flight
3happening last nightLondon stocks ended higher, fueled by overnight gains on Wall Street.
4overnight money is lent for one night and must be paid back the next dayCredit was tightened and the cost of overnight money touched 10%.
overnight commercial paper
—overnight adverbadv