indulge vs ply

indulge is not a noun while ply is a noun.

Word	Noun	Adjective	Verb	Adverb
indulge	No	No	Yes	No
ply	Yes	No	Yes	No

As verbs, ply is a hypernym of indulge; that is, ply is a word with a broader meaning than indulge:

Other hypernyms of indulge include cater, provide, supply.

indulge (noun)	ply (noun)
	(usually in combinations) one of several layers of cloth or paper or wood as in plywood
	one of the strands twisted together to make yarn or rope or thread; often used in combination

indulge (verb)	ply (verb)
yield (to); give satisfaction to	give what is desired or needed, especially support, food or sustenance
enjoy to excess	use diligently
treat with excessive indulgence	wield vigorously
give free rein to	join together as by twisting, weaving, or molding
	travel a route regularly
	apply oneself diligently