fall in vs go off

fall in and go off both are verbs.

Word	Noun	Adjective	Verb	Adverb
fall in	No	No	Yes	No
go off	No	No	Yes	No

As verbs, go off is a hyponym of fall in; that is, go off is a word with a more specific, narrower meaning than fall in:

Other hyponyms of fall in include implode, buckle, crumple, flop, break, sink, slide down, slump.

fall in (verb)	go off (verb)
break down, literally or metaphorically	be discharged or activated
become part of; become a member of a group or organization	happen in a particular manner
to take one's place in a military formation or line	burst inward
	go off or discharge
	stop running, functioning, or operating
	run away; usually includes taking something or somebody along