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hidden reserves of strength; latent energy; potentiality; real strength
チームは底力を発揮した。
The team showed their hidden strength.
彼は窮地で底力を出した。
He showed his hidden strength when cornered.
厳しい状況でも、彼は底力を出して乗り切った。
Even in a tough situation, he pulled through by drawing on his hidden strength.