overnight

Universal Words adverb, adjective adverb 1 during or for the night: We stayed overnight in London after the theatre. 2 suddenly or quickly: Don't expect it to improve overnight. * She became famous overnight. adjective [onlybeforenoun] 1 happening during the night; for a night: an overnight flight * overnight accommodation * She took only an overnight bag (= containing the things needed for a night spent away from home). 2 happening suddenly or quickly: The play was an overnight success.