intervene vs intervenor

intervene is not a noun while intervenor is a noun.

Word	Noun	Adjective	Verb	Adverb
intervene	No	No	Yes	No
intervenor	Yes	No	No	No

intervene (noun)	intervenor (noun)
	(law) a party who interposes in a pending proceeding

intervene (verb)	intervenor (verb)
occur between other event or between certain points of time
get involved, so as to alter or hinder an action, or through force or threat of force
be placed or located between other things or extend between spaces and events