welsher vs gouger

welsher and gouger both are nouns.

Word	Noun	Adjective	Verb	Adverb
welsher	Yes	No	No	No
gouger	Yes	No	No	No

As nouns, gouger is a hypernym of welsher; that is, gouger is a word with a broader meaning than welsher:

Other hypernyms of welsher include chiseler, chiseller, defrauder, grifter, scammer, swindler.

welsher (noun)	gouger (noun)
someone who swindles you by not repaying a debt or wager	a person who swindles you by means of deception or fraud
	an attacker who gouges out the antagonist's eye