fall in vs burst

fall in is not a noun while burst is a noun.

Word	Noun	Adjective	Verb	Adverb
fall in	No	No	Yes	No
burst	Yes	No	Yes	No

fall in (noun)	burst (noun)
	the act of exploding or bursting
	rapid simultaneous discharge of firearms
	a sudden flurry of activity (often for no obvious reason)
	a sudden intense happening

fall in (verb)	burst (verb)
break down, literally or metaphorically	come open suddenly and violently, as if from internal pressure
become part of; become a member of a group or organization	break open or apart suddenly and forcefully
to take one's place in a military formation or line	emerge suddenly
	burst outward, usually with noise
	force out or release suddenly and often violently something pent up
	move suddenly, energetically, or violently
	cause to burst
	be in a state of movement or action