What is the meaning of inexorable?

adjective

• Not to be placated or appeased or moved by entreaty.
  • usage: "grim determination"; "grim necessity"; "Russia's final hour, it seemed, approached with inexorable certainty"; "relentless persecution"; "the stern demands of parenthood"
  • synonyms: grim, relentless, stern, unappeasable, unforgiving, unrelenting
• Impervious to pleas, persuasion, requests, reason.
  • usage: "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"
  • synonyms: adamant, adamantine, intransigent