destiny vs happening

destiny and happening both are nouns.

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

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

destiny: an event (or a course of events) that will inevitably happen in the future
happening: an event that happens

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

destiny (noun)	happening (noun)
an event (or a course of events) that will inevitably happen in the future	an event that happens
the ultimate agency regarded as predetermining the course of events
your overall circumstances or condition in life (including everything that happens to you)