Definition of indomitableness in US English:

indomitableness

noun

  • See indomitable

    • ‘Of negligible military value, the revolt became a symbol of the indomitableness of the human spirit.’
    • ‘Were it a testimony to the indomitableness of human nature, it would be crushing.’
    • ‘It also speaks to the indomitableness of the human spirit in the face of even the most severe restrictions.’