To utter the farewell “good night”.

plural of night air

(obsolete) A miasma, or noxious atmosphere. / Used other than figuratively or idiomatically: see night, air.

(US) An inexpensive, easily obtained handgun. / (business) An unexpected takeover bid that gives its opponents little time to respond.

(political philosophy) A government with the least necessary power over its citizens.

(Britain) The revelry on Guy Fawkes Day (the 5th of November) in commemoration of the failure of the Gunpowder Plot of 1605, traditionally including the burning of effigies of the pope, Guy Fawkes, and/or the Devil.

Constantly; ceaselessly; without stopping.

An occasion when a performer or team of them (especially in vaudeville) expects to perform at a theater for a single evening.

Alternative spelling of Saturday-night special

(dated) A person whose occupation it was to collect the contents of chamber pots (faeces) in the morning from domestic households, principally in the 18th and 19th centuries.