human foot vs splayfoot

human foot and splayfoot both are nouns.

Word	Noun	Adjective	Verb	Adverb
human foot	Yes	No	No	No
splayfoot	Yes	Yes	No	No

As nouns, splayfoot is a hyponym of human foot; that is, splayfoot is a word with a more specific, narrower meaning than human foot:

human foot: the part of the leg of a human being below the ankle joint
splayfoot: a foot afflicted with a fallen arch; abnormally flattened and spread out

Other hyponyms of human foot include flatfoot, pes planus.

human foot (noun)	splayfoot (noun)
the part of the leg of a human being below the ankle joint	a foot afflicted with a fallen arch; abnormally flattened and spread out

human foot (adjective)	splayfoot (adjective)
	having feet that turn outward