expression vs phrase

expression and phrase both are nouns.

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

As nouns, phrase is a hyponym of expression; that is, phrase is a word with a more specific, narrower meaning than expression:

expression: a word or phrase that particular people use in particular situations
phrase: an expression whose meanings cannot be inferred from the meanings of the words that make it up

As nouns, phrase is a hyponym of expression; that is, phrase is a word with a more specific, narrower meaning than expression:

expression: a group of words that form a constituent of a sentence and are considered as a single unit
phrase: an expression consisting of one or more words forming a grammatical constituent of a sentence

Other hyponyms of expression include adjunct, clause, complement, involution, predicator.

expression (noun)	phrase (noun)
the act of forcing something out by squeezing or pressing	dance movements that are linked in a single choreographic sequence
the feelings expressed on a person's face	an expression consisting of one or more words forming a grammatical constituent of a sentence
a word or phrase that particular people use in particular situations	a short musical passage
the style of expressing yourself	an expression whose meanings cannot be inferred from the meanings of the words that make it up
expression without words
a group of symbols that make a mathematical statement
the communication (in speech or writing) of your beliefs or opinions
a group of words that form a constituent of a sentence and are considered as a single unit
(genetics) the process of expressing a gene

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