nightcap

n 1 (formerly) soft cap worn in bed （旧时）睡帽. 2 (usu alcoholic) drink taken before going to bed 睡前的饮料（通常指酒）.

night after night, night and day, night porter, night safe, night shift, night-bird, night-blindness, night-club, night-gown, night-life, night-light, night-line, night-long, night-school, night-shirt, night-soil, night-staff, night-time, night-watch, night-watchman, nightfall, nightgown, nightie (also nighty), nightingale, nightjar, nightly, nightmare, nightmarish, nights, nightshade, nightshirt, nightstick, nihilism, nihilist, nihilistic, nil, Nile, nimble, nimbleness, nimbly,