inroad vs invasion

inroad and invasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
inroad	Yes	No	No	No
invasion	Yes	No	No	No

As nouns, invasion is a hypernym of inroad; that is, invasion is a word with a broader meaning than inroad:

inroad: an invasion or hostile attack
invasion: the act of invading; the act of an army that invades for conquest or plunder

inroad (noun)	invasion (noun)
an invasion or hostile attack	the act of invading; the act of an army that invades for conquest or plunder
an encroachment or intrusion	any entry into an area not previously occupied
	(pathology) the spread of pathogenic microorganisms or malignant cells to new sites in the body