phrase vs head word

phrase and head word both are nouns.

Word	Noun	Adjective	Verb	Adverb
phrase	Yes	No	Yes	No
head word	Yes	No	No	No

phrase (noun)	head word (noun)
dance movements that are linked in a single choreographic sequence	(grammar) the word in a grammatical constituent that plays the same grammatical role as the whole constituent
an expression consisting of one or more words forming a grammatical constituent of a sentence	a content word that can be qualified by a modifier
a short musical passage
an expression whose meanings cannot be inferred from the meanings of the words that make it up

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