doubleheader vs nightcap

doubleheader and nightcap both are nouns.

Word	Noun	Adjective	Verb	Adverb
doubleheader	Yes	No	No	No
nightcap	Yes	No	No	No

doubleheader (noun)	nightcap (noun)
two games instead of one (especially in baseball when the same two teams play two games on the same day)	the final game of a double header
	a cloth cap worn in bed
	an alcoholic drink taken at bedtime; often alcoholic