chap vs fissure

chap and fissure both are nouns.

Word	Noun	Adjective	Verb	Adverb
chap	Yes	No	Yes	No
fissure	Yes	No	Yes	No

As nouns, fissure is a hypernym of chap; that is, fissure is a word with a broader meaning than chap:

Other hypernyms of chap include cleft, crack, crevice, scissure.

As nouns, chap and fissure are synonyms defined as:

Other synonyms of chap include crack, cranny, crevice.

chap (noun)	fissure (noun)
(usually in the plural) leather leggings without a seat; joined by a belt; often have flared outer flaps; worn over trousers by cowboys to protect their legs	(anatomy) a long narrow slit or groove that divides an organ into lobes
a crack in a lip caused usually by cold	a long narrow cleft
a boy or man	a long narrow depression in a surface
a long narrow depression in a surface

chap (verb)	fissure (verb)
crack due to dehydration	break into fissures or fine cracks