1. an alcoholic drink taken at bedtime; often alcoholic

Definition categories: food, drink

2. a cloth cap worn in bed

Definition categories: man–made, cap

3. the final game of a double header

Definition categories: act, game

Sentences with nightcap as a noun:

- Winston wore a nightcap to stave off the cold.

- I'll make myself a nightcap of whisky and lemon before heading to bed.