expression, noun
Euphemistic, literary expression for sexual activity, literally 'night's work' or 'nightly activities'. Used to refer to sex indirectly, often in a poetic or discreet manner.
夫婦は夜の営みを大切にしている。
The couple cherishes their nightly intimacy.
小説には夜の営みの描写が含まれている。
The novel contains descriptions of sexual encounters.