ride horseback vs trot

ride horseback is not a noun while trot is a noun.

Word	Noun	Adjective	Verb	Adverb
ride horseback	No	No	Yes	No
trot	Yes	No	Yes	No

As verbs, trot is a hyponym of ride horseback; that is, trot is a word with a more specific, narrower meaning than ride horseback:

Other hyponyms of ride horseback include prance, canter, gallop, post.

ride horseback (noun)	trot (noun)
	a slow pace of running
	a gait faster than a walk; diagonally opposite legs strike the ground together
	a literal translation used in studying a foreign language (often used illicitly)

ride horseback (verb)	trot (verb)
ride on horseback	run at a moderately swift pace
	ride at a trot
	cause to trot