invasion vs medical specialty

invasion and medical specialty both are nouns.

Word	Noun	Adjective	Verb	Adverb
invasion	Yes	No	No	No
medical specialty	Yes	No	No	No

invasion (noun)	medical specialty (noun)
the act of invading; the act of an army that invades for conquest or plunder	the branches of medical science that deal with nonsurgical techniques
any entry into an area not previously occupied
(pathology) the spread of pathogenic microorganisms or malignant cells to new sites in the body