Definitions: (1) resistance to fatigue, illness, stress, or difficulty; (2) possessing staying power or endurance

Derivation: Latin, referring to the life-threads spun by the Fates

• Grit, in a word, is stamina. But it’s not just stamina in your effort. It’s also stamina in your direction, stamina in your interests. — Angela Lee Duckworth (1970-) American psychologist
• There is no problem that doesn’t have some underlying need for more optimism, stamina, resilience, and collaboration. — Jane McGonigal (1977-) American author