inroad vs intrusion

inroad and intrusion both are nouns.

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

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

Other hypernyms of inroad include encroachment, trespass, usurpation, violation.

inroad (noun)	intrusion (noun)
an invasion or hostile attack	entry to another's property without right or permission
an encroachment or intrusion	entrance by force or without permission or welcome
	any entry into an area not previously occupied
	rock produced by an intrusive process
	the forcing of molten rock into fissures or between strata of an earlier rock formation