happening vs occurrent

happening and occurrent both are nouns.

Word	Noun	Adjective	Verb	Adverb
happening	Yes	No	No	No
occurrent	Yes	Yes	No	No

As nouns, happening and occurrent are synonyms defined as:

Other synonyms of happening include natural event, occurrence.

happening (noun)	occurrent (noun)
an event that happens	an event that happens

happening (adjective)	occurrent (adjective)
	presently occurring (either causally or incidentally)