roam vs gad

roam is not a noun while gad is a noun.

Word	Noun	Adjective	Verb	Adverb
roam	No	No	Yes	No
gad	Yes	No	Yes	No

As verbs, gad is a hyponym of roam; that is, gad is a word with a more specific, narrower meaning than roam:

roam: move about aimlessly or without any destination, often in search of food or employment
gad: wander aimlessly in search of pleasure

Other hyponyms of roam include maunder, gallivant, jazz around.

roam (noun)	gad (noun)
	a sharp prod fixed to a rider's heel and used to urge a horse onward

roam (verb)	gad (verb)
move about aimlessly or without any destination, often in search of food or employment	wander aimlessly in search of pleasure