incision vs thoracotomy

incision and thoracotomy both are nouns.

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

As nouns, thoracotomy is a hyponym of incision; that is, thoracotomy 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)
thoracotomy: surgical incision into the chest walls opening up the pleural cavity

incision (noun)	thoracotomy (noun)
the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)	surgical incision into the chest walls opening up the pleural cavity
a depression scratched or carved into a surface