unpardonable

/ʌnˈpɑːrdənəbəl/
adjective
  1. Too bad to be forgiven or excused.
    • The company's neglect of safety rules was an unpardonable mistake.
    • He considered her rudeness unpardonable and ended the friendship.
    • Betraying a friend's trust is an unpardonable sin in her eyes.
What does "unpardonable" mean? | whatsthatwordmean | whatsthatwordmean