inexorable

adjectives

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"
is derived from
is derived from
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"
is derived from