[ adj ] not liable to being annulled or voided or undone <adj.all> an indefeasible right to freedoman indefeasible claim to the title
Indefeasible \In`de*fea`si*ble\, a. [Pref. in- not + defeasible: cf. OF. indefaisable.] 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.