concomitant vs happening

concomitant and happening both are nouns.

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

As nouns, happening is a hypernym of concomitant; that is, happening is a word with a broader meaning than concomitant:

concomitant: an event or situation that happens at the same time as or in connection with another
happening: an event that happens

Other hypernyms of concomitant include natural event, occurrence, occurrent.

concomitant (noun)	happening (noun)
an event or situation that happens at the same time as or in connection with another	an event that happens

concomitant (adjective)	happening (adjective)
occurring with or following as a consequence