ostinato vs phrase

ostinato and phrase both are nouns.

Word	Noun	Adjective	Verb	Adverb
ostinato	Yes	No	No	No
phrase	Yes	No	Yes	No

As nouns, phrase is a hypernym of ostinato; that is, phrase is a word with a broader meaning than ostinato:

Other hypernyms of ostinato include musical phrase.

ostinato (noun)	phrase (noun)
a musical phrase repeated over and over during a composition	dance movements that are linked in a single choreographic sequence
	an expression consisting of one or more words forming a grammatical constituent of a sentence
	a short musical passage
	an expression whose meanings cannot be inferred from the meanings of the words that make it up

ostinato (verb)	phrase (verb)
	put into words or an expression
	divide, combine, or mark into phrases