inexorable

Meanings

• not to be placated or appeased or moved by entreaty
  • "Russia's final hour, it seemed, approached with inexorable certainty"
• impervious to pleas, persuasion, requests, reason; ; - W.Churchill
  • "Cynthia was inexorable; she would have none of him"

Synonyms

adamant, adamantine, grim, intransigent, relentless, stern, unappeasable, unforgiving, unrelenting