Finnish： Sisu (n) perseverance, grit. Sisu (Phonetic text)

Example:

“Sisu” is a Finnish word for the psychological strength that allows a person to overcome extraordinary challenges. “Sisu” is similar to what an American might call perseverance or the trendier concept of grit. But “sisu” has no real equivalent in English. “Sisu” connotes both determination and bravery, a willingness to act even when the reward seems out of reach.