event vs aftereffect

event and aftereffect both are nouns.

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

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

event (noun)	aftereffect (noun)
something that happens at a given place and time	any result that follows its cause after an interval
a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory	a delayed effect of a drug or therapy
a phenomenon that follows and is caused by some previous phenomenon
a special set of circumstances