gad vs roam

gad is a noun but roam is not a noun.

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

As verbs, roam is a hypernym of gad; that is, roam is a word with a broader meaning than gad:

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

Other hypernyms of gad include cast, drift, ramble, range, roll, rove, stray, swan, tramp, vagabond, wander.

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

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