In·de·fea·si·ble a. Not to be defeated; not defeasible; incapable of being annulled or made void; as, an indefeasible or title.
That the king had a divine and an indefeasible right to the regal power. --Macaulay.
adj : not liable to being annulled or voided or undone; "an
indefeasible right to freedom"; "an indefeasible claim
to the title" [ant: defeasible]