用心深い
彼は用心深い人で、夜道を一人で歩くことは決してしない。
He's a cautious person and would never walk alone at night.
Very careful to avoid potential danger or trouble; vigilant and watchful.
用心深い運転手は、雨の日にいつも速度を落として走る。
A cautious driver always slows down when driving in the rain.
彼女は用心深く財布を手に持って、人混みの中を歩いた。
She held her wallet tightly and walked carefully through the crowd.
Emphasizes proactive care rather than just being alert. Often used for people's attitudes or behaviors.
Pro Tip
Avoid overusing for objects
While 用心深い can describe cautious actions, it primarily describes people's attitudes. For objects (e.g., a lock), use 頑丈な (sturdy) or 頑強な (robust) instead.
Gold Rule
Contrast with 注意深い
注意深い emphasizes attention to detail, while 用心深い focuses on avoiding danger or harm. 注意深い is more neutral, whereas 用心深い implies a sense of wariness or suspicion.
Word Origin
From 用心 (youjin, 'care/precaution') + 深い (fukai, 'deep/intense'). The compound describes a state of being deeply cautious or vigilant.
Usage Notes
Commonly describes people's habitual behavior rather than a one-time action. Often paired with verbs like 歩く (walk), 運転する (drive), or 振る舞う (act).