intermission vs interval

intermission and interval both are nouns.

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

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

intermission: a time interval during which there is a temporary cessation of something
interval: a definite length of time marked off by two instants

Other hypernyms of intermission include time interval.

intermission (noun)	interval (noun)
the act of suspending activity temporarily	the distance between things
a time interval during which there is a temporary cessation of something	a set containing all points (or all real numbers) between two given endpoints
	the difference in pitch between two notes
	a definite length of time marked off by two instants