mettle Meaning, Definition & Usage

  1. noun the courage to carry on
    heart; spunk; nerve.
    • he kept fighting on pure spunk
    • you haven't got the heart for baseball

WordNet

Met"tle noun
Etymology
E. metal, used in a tropical sense in allusion to the temper of the metal of a sword blade. See Metal.
Definitions
  1. Substance or quality of temperament; spirit, esp. as regards honor, courage, fortitude, ardor, etc.; disposition; -- usually in a good sense.
    A certain critical hour which shall... try what mettle his heart is made of. South.
    Gentlemen of brave mettle. Shak.
    The winged courser, like a generous horse, Shows most true mettle when you check his course. Pope.

Webster 1913