encroachment vs invasion

encroachment and invasion both are nouns.

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

As nouns, encroachment and invasion are synonyms defined as:

encroachment and invasion: any entry into an area not previously occupied

Other synonyms of encroachment include intrusion.

encroachment (noun)	invasion (noun)
entry to another's property without right or permission	the act of invading; the act of an army that invades for conquest or plunder
influencing strongly	any entry into an area not previously occupied
any entry into an area not previously occupied	(pathology) the spread of pathogenic microorganisms or malignant cells to new sites in the body