honor guard vs guard of honor

honor guard and guard of honor both are nouns.

Word	Noun	Adjective	Verb	Adverb
honor guard	Yes	No	No	No
guard of honor	Yes	No	No	No

As nouns, honor guard and guard of honor are synonyms defined as:

honor guard and guard of honor: an escort for a distinguished guest or for the casket at a military funeral

honor guard (noun)	guard of honor (noun)
an escort for a distinguished guest or for the casket at a military funeral	an escort for a distinguished guest or for the casket at a military funeral