Dictionary / Vocabulary / 油断なく
ゆだんなく
alertly; vigilantly; warily; diligently
Also written 油断無く
油断なく注意さえしておれば好機はおのずからうまれる。
Plenty of opportunities will present themselves, if only you are awake to them.
逃亡犯人を捕まえようと油断なく見張った。
I was on the alert for a fugitive criminal.