To steel oneself; to make up one's mind and resolve to face a difficult or worst-case situation—decide firmly to act.
手術を受けるとき、彼女は覚悟を決めて家族に感謝を伝えた。
When facing the surgery, she steeled herself and expressed gratitude to her family.
給料が下がるかもしれないが、夢のために覚悟を決めて独立することにした。
Even though my salary might drop, I resolved to go independent for the sake of my dream.
覚悟を決めた顔つきで、彼は最後のプレゼンに向かって歩き出した。
With a resolute look, he walked toward his final presentation.