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warrior (esp. of military retainers of daimyos in the Edo period); samurai
person with a strong backbone; person that does incredible things; person of considerable talent
「士」 has another reading with different meanings.
士の精神は忠義と名誉を重んじるものだった。
The warrior spirit valued loyalty and honor.
映画に描かれた士の生き様に感銘を受けた。
I was moved by the way of life of the samurai depicted in the film.
士は主君のために命を懸けて戦う覚悟を持っていた。
The samurai was prepared to risk his life fighting for his lord.