油断も隙もない

ゆだんもすきもない

Also written 油断も隙も無い

Meanings

1. Expression one must constantly be on one's guard with ...; one cannot be too careful of ...

Kanji

• 油 oil. Read as ユ.
• 断 sever. Read as ダン.
• 隙 crevice. Read as すき.

Jinuma: Japanese Dictionary · Word lists