catchphrase vs catchword

catchphrase and catchword both are nouns.

Word	Noun	Adjective	Verb	Adverb
catchphrase	Yes	No	No	No
catchword	Yes	No	No	No

As nouns, catchword is a hypernym of catchphrase; that is, catchword is a word with a broader meaning than catchphrase:

Other hypernyms of catchphrase include phrase, motto, shibboleth, slogan.

catchphrase (noun)	catchword (noun)
a phrase that has become a catchword	a favorite saying of a group, organization or individual
	a word printed at the top of the page of a dictionary or other reference book to indicate the first or last item on that page