encroachment vs impact

encroachment and impact both are nouns.

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

As nouns, encroachment and impact are synonyms defined as:

Other synonyms of encroachment include impingement.

encroachment (noun)	impact (noun)
entry to another's property without right or permission	influencing strongly
influencing strongly	the violent interaction of individuals or groups entering into combat
any entry into an area not previously occupied	the striking of one body against another
	a forceful consequence; a strong effect

encroachment (verb)	impact (verb)
	have an effect upon
	press or wedge together; pack together