stout heart; strong mind
Refers to mental fortitude, resilience, or an unwavering spirit. Often used in motivational or character-describing contexts.
I want to have a strong mind that won't be defeated by hardship.
Her stout heart supports the team.
A straightforward compound of 強い (strong) and 心 (heart/mind). The exact historical derivation is uncertain, but the phrase has been used in Japanese to describe mental fortitude.