Mettle (noun)

1. The quality of being determined and resilient in the face of difficult situations.
2. The inner strength and character of a person, especially in adversity.

Origin:

Derives from old english "mete" which means "food" and later "mettle" which means "quality" and "nature".

Examples:

1. The test of adversity revealed his true mettle.
2. The soldier showed great mettle under fire.
3. The company was put to the test, but it stood its ground and showed its mettle.
4. The athlete showed great mettle by coming back from a serious injury.
5. The young leader's mettle was tested during the crisis and he emerged victorious.