knock-on effect vs event

knock-on effect and event both are nouns.

Word	Noun	Adjective	Verb	Adverb
knock-on effect	Yes	No	No	No
event	Yes	No	No	No

As nouns, event is a hypernym of knock-on effect; that is, event is a word with a broader meaning than knock-on effect:

Other hypernyms of knock-on effect include consequence, effect, issue, outcome, result, upshot.

knock-on effect (noun)	event (noun)
a secondary or incidental effect	something that happens at a given place and time
	a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory
	a phenomenon that follows and is caused by some previous phenomenon
	a special set of circumstances