lesion vs gash

lesion and gash both are nouns.

Word	Noun	Adjective	Verb	Adverb
lesion	Yes	No	No	No
gash	Yes	No	Yes	No

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

lesion: an injury to living tissue (especially an injury involving a cut or break in the skin)
gash: a wound made by cutting

Other hyponyms of lesion include raw wound, stigmata, abrasion, excoriation, scrape, scratch, cut, slash, slice, laceration, bite.

lesion (noun)	gash (noun)
any localized abnormal structural change in a bodily part	a strong sweeping cut made with a sharp instrument
an injury to living tissue (especially an injury involving a cut or break in the skin)	a trench resembling a furrow that was made by erosion or excavation
	a wound made by cutting

lesion (verb)	gash (verb)
	cut open