(often used adverbially) The evening or night immediately before the present.

during the previous day’s nighttime; during the night before today

During the night of the day after the present day.

The night of the day after the present day.

A farewell said in the evening or before going to sleep. / (colloquial, dated) Expressing incredulity.

(literally) An owl (order Strigiformes) that is nocturnal. / (idiomatic) One who goes to bed late, or stays up late at night or in the early hours of the morning.

(obsolete) A loose robe worn as a nightgown.

Lasting throughout the whole night (or most of it)

(UK) Synonym of Guy Fawkes Night

A watch kept on some premises, or on a town, by guards during the night. / One or more of the guards on such a watch.