noun
night watchman; night guard
Refers to a person who patrols or guards a building or area at night. Often used in contexts like security companies, museums, or historical settings.
夜警が毎晩、建物の周りを見回っている。
The night watchman patrols around the building every night.
美術館は夜警を雇って貴重な展示品を守って
The museum hires a night guard to protect its valuable exhibits.
Compound of 夜 (night) and 警 (guard/watch). The exact historical derivation is uncertain, but the meaning is transparent from the kanji.