flare up vs irrupt

flare up and irrupt both are verbs.

Word	Noun	Adjective	Verb	Adverb
flare up	No	No	Yes	No
irrupt	No	No	Yes	No

As verbs, flare up and irrupt are synonyms defined as:

Other synonyms of flare up include break open, burst out, erupt, flare.

flare up (verb)	irrupt (verb)
erupt or intensify suddenly	increase rapidly and in an uncontrolled manner
ignite quickly and suddenly, especially after having died down	erupt or intensify suddenly
	enter uninvited