In`de*fen"si*ble (?), [Pref. in- not + defensible: cf. OF. indefensible, indefensable.]
Not defensible; not capable of being defended, maintained, vindicated, or justified; unjustifiable; untenable; as, an indefensible fortress, position, cause, etc.
Men find that something can be said in favor of what, on the very proposal, they thought utterly indefensible.
© Webster 1913.