guide word vs catchword

guide word and catchword both are nouns.

Word	Noun	Adjective	Verb	Adverb
guide word	Yes	No	No	No
catchword	Yes	No	No	No

As nouns, guide word and catchword are synonyms defined as:

guide word and catchword: 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

Other synonyms of guide word include guideword.

guide word (noun)	catchword (noun)
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	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