inexorable

(s) not to be placated or appeased or moved by entreaty
- grim determination
- grim necessity
- Russia's final hour, it seemed, approached with inexorable certainty
- relentless persecution
- the stern demands of parenthood
grim, relentless, unappeasable, unrelenting, stern, unforgiving,
(s) impervious to pleas, persuasion, requests, reason
- he is adamant in his refusal to change his mind
- "Cynthia was inexorable; she would have none of him"- W.Churchill
- an intransigent conservative opposed to every liberal tendency
adamant, intransigent, adamantine,

grim relentless unappeasable unrelenting stern unforgiving adamant intransigent adamantine

inexorably

inexorableness