catchword vs motto

catchword and motto both are nouns.

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

As nouns, catchword and motto are synonyms defined as:

catchword and motto: a favorite saying of a group, organization or individual

Other synonyms of catchword include shibboleth, slogan.

catchword (noun)	motto (noun)
a favorite saying of a group, organization or individual	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