intervene vs hap

intervene is not a noun while hap is a noun.

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

As verbs, hap is a hypernym of intervene; that is, hap is a word with a broader meaning than intervene:

Other hypernyms of intervene include come about, fall out, go on, happen, occur, pass, pass off, take place.

intervene (noun)	hap (noun)
	an accidental happening

intervene (verb)	hap (verb)
occur between other event or between certain points of time	come to pass
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