encroach upon vs invade

encroach upon and invade both are verbs.

Word	Noun	Adjective	Verb	Adverb
encroach upon	No	No	Yes	No
invade	No	No	Yes	No

As verbs, encroach upon and invade are synonyms defined as:

encroach upon and invade: to intrude upon, infringe, encroach on, violate

Other synonyms of encroach upon include intrude on, obtrude upon.

encroach upon (verb)	invade (verb)
to intrude upon, infringe, encroach on, violate	march aggressively into another's territory by military force for the purposes of conquest and occupation
	penetrate or assault, in a harmful or injurious way
	to intrude upon, infringe, encroach on, violate
	occupy in large numbers or live on a host