trigger vs fall out

trigger is a noun but fall out is not a noun.

Word	Noun	Adjective	Verb	Adverb
trigger	Yes	No	Yes	No
fall out	No	No	Yes	No

trigger (noun)	fall out (noun)
an act that sets in motion some course of events
lever that activates the firing mechanism of a gun
a device that activates or releases or causes something to happen

trigger (verb)	fall out (verb)
release or pull the trigger on	come to pass
put in motion or move to act	have a breach in relations
	drop out
	leave (a barracks) in order to take a place in a military formation, or leave a military formation
	come as a logical consequence; follow logically