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careful; cautious; wary; watchful; vigilant; prudent
彼女は昔から用心深かった。
She has always been cautious.
用心深く周囲を見渡してから部屋に入った。
I looked around carefully before entering the room.
用心深い人ほど騙されにくい。
The more cautious a person is, the harder they are to fool.