event vs outgrowth

event and outgrowth both are nouns.

Word	Noun	Adjective	Verb	Adverb
event	Yes	No	No	No
outgrowth	Yes	No	No	No

As nouns, outgrowth is a hyponym of event; that is, outgrowth is a word with a more specific, narrower meaning than event:

event (noun)	outgrowth (noun)
something that happens at a given place and time	a natural prolongation or projection from a part of an organism either animal or plant
a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory	the gradual beginning or coming forth
a phenomenon that follows and is caused by some previous phenomenon	a natural consequence of development
a special set of circumstances