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cowardly; timid; easily frightened
憶病な性格のせいで新しいことに挑戦できない。
Because of my timid nature, I cannot take on new challenges.
彼は見た目と違って意外と憶病なところがある。
Contrary to his appearance, he has a surprisingly timid side.
憶病にならず、自分の意見をはっきり言うべきだ。
You should not be timid and should state your opinion clearly.