intrusion vs inroad

intrusion and inroad both are nouns.

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

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

intrusion (noun)	inroad (noun)
entry to another's property without right or permission	an invasion or hostile attack
entrance by force or without permission or welcome	an encroachment or intrusion
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