nightcap vs doubleheader

nightcap and doubleheader both are nouns.

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

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