不ぶ用よう心じん

na-adjective, noun

unsafe; insecure; careless; dangerous

Describes a situation, place, or behavior that is not safe or secure, often implying a lack of caution or vigilance. Used for physical security as well as personal carelessness.

• 夜よ道みちを一人ひとりで歩あるくのは不ぶ用よう心じんだ。

  It's unsafe to walk alone on the street at night.

• 鍵かぎをかけないなんて不ぶ用よう心じんですね。

  It's careless not to lock the door, isn't it?