corpulency vs stoutness

corpulency and stoutness both are nouns.

Word	Noun	Adjective	Verb	Adverb
corpulency	Yes	No	No	No
stoutness	Yes	No	No	No

As nouns, stoutness is a hyponym of corpulency; that is, stoutness is a word with a more specific, narrower meaning than corpulency:

Other hyponyms of corpulency include adiposis, corpulence, overweight, exogenous obesity, embonpoint, plumpness, roundness.

corpulency (noun)	stoutness (noun)
more than average fatness	the property of excessive fatness
	the property of being strong and resolute