callosity vs clavus

callosity and clavus both are nouns.

Word	Noun	Adjective	Verb	Adverb
callosity	Yes	No	No	No
clavus	Yes	No	No	No

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

callosity: an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot)
clavus: a hard thickening of the skin (especially on the top or sides of the toes) caused by the pressure of ill-fitting shoes

Other hyponyms of callosity include corn.

callosity (noun)	clavus (noun)
devoid of passion or feeling; hardheartedness	a hard thickening of the skin (especially on the top or sides of the toes) caused by the pressure of ill-fitting shoes
an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot)