insupportable vs indefensible

insupportable and indefensible both are adjectives.

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

As adjectives, insupportable and indefensible are synonyms defined as:

insupportable and indefensible: incapable of being justified or explained

Other synonyms of insupportable include unjustifiable, unwarrantable, unwarranted.

insupportable (adjective)	indefensible (adjective)
incapable of being justified or explained	incapable of being justified or explained
	(of theories etc) incapable of being defended or justified
	not able to be protected against attack