Wiktionary
adv. In an indefeasible manner.
Usage examples of "indefeasibly".
It is—we say it without censure, nor in diminution of the claim which it indefeasibly possesses on beings of another mold—it is always selfish in its essence, and we must give it leave to be so, and heap up our heroic and disinterested love upon it so much the more, without a recompense.
So even if in desperation 'the West' had bred or hired hordes of ores and had cruelly ravaged the lands of other Men as allies of Sauron, or merely to prevent them from aiding him, their Cause would have remained indefeasibly right.
In that city, then, there shall be free will, one in all the citizens, and indivisible in each, delivered from all ill, filled with all good, enjoying indefeasibly the delights of eternal joys, oblivious of sins, oblivious of sufferings, and yet not so oblivious of its deliverance as to be ungrateful to its Deliverer.