spark off vs trigger

spark off is not a noun while trigger is a noun.

Word	Noun	Adjective	Verb	Adverb
spark off	No	No	Yes	No
trigger	Yes	No	Yes	No

As verbs, spark off and trigger are synonyms defined as:

Other synonyms of spark off include activate, actuate, set off, spark, touch off, trigger off, trip.

spark off (noun)	trigger (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

spark off (verb)	trigger (verb)
put in motion or move to act	release or pull the trigger on
	put in motion or move to act