incision vs nephrotomy

incision and nephrotomy both are nouns.

Word	Noun	Adjective	Verb	Adverb
incision	Yes	No	No	No
nephrotomy	Yes	No	No	No

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

incision: the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)
nephrotomy: incision into a kidney (usually to remove a kidney stone)

incision (noun)	nephrotomy (noun)
the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)	incision into a kidney (usually to remove a kidney stone)
a depression scratched or carved into a surface