油ゆ断だんは禁きん物もつ

expression

be on your guard!; take care!

Proverb warning against letting one's guard down; literally 'carelessness is forbidden'. Used as a standalone admonition or within a sentence.

• 油ゆ断だんは禁きん物もつだ。もう一いち度ど確かく認にんしよう。

  You mustn't let your guard down. Let's check once more.

• 試し験けんが終おわっても油ゆ断だんは禁きん物もつです。

  Even after the exam is over, you must stay vigilant.