undefended vs undefendable

undefended and undefendable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
undefended	No	Yes	No	No
undefendable	No	Yes	No	No

As adjectives, undefended and undefendable are synonyms defined as:

Other synonyms of undefended include assailable, open.

undefended (adjective)	undefendable (adjective)
not defended or capable of being defended	not defended or capable of being defended