insupportable vs unwarranted

insupportable and unwarranted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
insupportable	No	Yes	No	No
unwarranted	No	Yes	No	No

As adjectives, insupportable and unwarranted are synonyms defined as:

insupportable and unwarranted: incapable of being justified or explained

Other synonyms of insupportable include indefensible, unjustifiable, unwarrantable.

insupportable (adjective)	unwarranted (adjective)
incapable of being justified or explained	incapable of being justified or explained
	lacking justification or authorization
	without a basis in reason or fact