impregnate vs stuff

impregnate is not a noun while stuff is a noun.

Word	Noun	Adjective	Verb	Adverb
impregnate	No	No	Yes	No
stuff	Yes	No	Yes	No

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

Other hyponyms of impregnate include medicate, alcoholise, alcoholize, imbue, soak, ammonify, thoriate, charge, drench, imbrue.

impregnate (noun)	stuff (noun)
	miscellaneous unspecified objects
	unspecified qualities required to do or be something
	a critically important or characteristic component
	senseless talk
	information in some unspecified form
	informal terms for personal possessions
	the tangible substance that goes into the makeup of a physical object

impregnate (verb)	stuff (verb)
make pregnant	fill with a stuffing while cooking
fertilize and cause to grow	fill tightly with a material
infuse or fill completely	treat with grease, fill, and prepare for mounting
fill, as with a certain quality	overeat or eat immodestly; make a pig of oneself
	cram into a cavity
	obstruct
	press or force