[over.night] adv (14c) 1 a: on the evening before b: during the night "stayed away ~"
2: very quickly or suddenly "became famous ~"
[2]overnight adj (1824) 1: of, lasting, or staying the night
2: sudden, rapid "an ~ sensation" [3]overnight vi (1891): to stay overnight [4]over.night n (1959): an overnight stay