mitigate vs rationalise

mitigate and rationalise both are verbs.

Word	Noun	Adjective	Verb	Adverb
mitigate	No	No	Yes	No
rationalise	No	No	Yes	No

As verbs, rationalise is a hypernym of mitigate; that is, rationalise is a word with a broader meaning than mitigate:

Other hypernyms of mitigate include apologise, apologize, excuse, rationalize.

mitigate (verb)	rationalise (verb)
to temper	weed out unwanted or unnecessary things
lessen or to try to lessen the seriousness or extent of	remove irrational quantities from
	think rationally; employ logic or reason
	defend, explain, clear away, or make excuses for by reasoning
	structure and run according to rational or scientific principles in order to achieve desired results