Nightcap

[Tina]

a drink (usually whisky/whiskey) taken at bedtime to aid a better sleep.

[Donald Trump]

Sex (thinly veiled euphemism for)

[Becky]

last drink of the night.

[PussyCat]

a alcoholic drink taken just before bedtime

[Britney]

traditionally, a drink had after dinner. or right before bed. as opposed to capping off a long night of drinking

[Zipporah Schumaker]

A cap worn in bed to protect the head, or in undress.

[Agnes]

An excuse to get a [hot date] from [the car] into her [apartment].

[Monty]

a late night [smoke session], specifically with the intent of [going to bed] immediately following said session.
to smoke by yourself right before bed, using the session as a sleep aid. ([potheads] swear by it)
can be a personal session, (by yourself) or a social session (with friends)

[Justin Bieber]

[A mans] [last chance] to get a woman drunk before the [date] is over.