run into vs encounter

run into is not a noun while encounter is a noun.

Word	Noun	Adjective	Verb	Adverb
run into	No	No	Yes	No
encounter	Yes	No	Yes	No

As verbs, run into and encounter are synonyms defined as:

Other synonyms of run into include come across, meet, run across, see.

As verbs, run into and encounter are synonyms defined as:

run into (noun)	encounter (noun)
	a minor short-term fight
	a casual meeting with a person or thing
	a hostile disagreement face-to-face
	a casual or unexpected convergence

run into (verb)	encounter (verb)
collide violently with an obstacle	contend against an opponent in a sport, game, or battle
hit against; come into sudden contact with	come together
come together	come upon, as if by accident; meet with
be beset by	be beset by
	experience as a reaction