Incapable of being reversed.

Roget 150: unchangeable, immutable; unaltered, unalterable; not to be changed, constant; permanent etc. 141; invariable, undeviating; stable, durable; perennial etc. (diuturnal) 110^†.    fixed, steadfast, firm, fast, steady, balanced; confirmed, valid; fiducial^†; immovable, irremovable, riveted, rooted; settled, established etc. v.; vested; incontrovertible, stereotyped, indeclinable.    tethered, anchored, moored, at anchor, on a rock, rock solid, firm as a rock; firmly seated, firmly established etc. v.; deep-rooted, ineradicable; inveterate; obstinate etc. 606.    transfixed, stuck fast, aground, high and dry, stranded.    [movable object rendered unmovable] stuck, jammed; unremovable; quiescent etc. 265; deterioration etc. 659.    indefeasible, irretrievable, intransmutable^†, incommutable^†, irresoluble^†, irrevocable, irreversible, reverseless^†, inextinguishable, irreducible; indissoluble, indissolvable^†; indestructible, undying, imperishable, incorruptible, indelible, indeciduous^†; insusceptible, insusceptible of change.    ... show more

Roget 859: hopeless, desperate, despairing, gone, in despair, au desespoir [Fr.], forlorn, desolate; inconsolable etc. (dejected) 837; broken hearted.    unpromising, unpropitious; inauspicious, ill-omened, threatening, clouded over.    out of the question, not to be thought of; impracticable etc. 471; past hope, past cure, past mending, past recall; at one's last gasp etc. (death) 360; given up, given over.    incurable, cureless, immedicable, remediless, beyond remedy; incorrigible; irreparable, irremediable, irrecoverable, irreversible, irretrievable, irreclaimable, irredeemable, irrevocable; ruined, undone; immitigable.    ... show more

Dutch: irreversibel, onomkeerbaar
Polish: nieodwracalny