halftime vs intermission

halftime and intermission both are nouns.

Word	Noun	Adjective	Verb	Adverb
halftime	Yes	No	No	No
intermission	Yes	No	No	No

As nouns, intermission is a hypernym of halftime; that is, intermission is a word with a broader meaning than halftime:

halftime: an intermission between the first and second half of a game
intermission: a time interval during which there is a temporary cessation of something

Other hypernyms of halftime include break, interruption, pause, suspension.

halftime (noun)	intermission (noun)
an intermission between the first and second half of a game	the act of suspending activity temporarily
	a time interval during which there is a temporary cessation of something