event vs fallout

event and fallout both are nouns.

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

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

event (noun)	fallout (noun)
something that happens at a given place and time	any adverse and unwanted secondary effect
a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory	the radioactive particles that settle to the ground after a nuclear explosion
a phenomenon that follows and is caused by some previous phenomenon
a special set of circumstances