on duty

Idioms  

1. At one's post, at work, as in The new nurse was on duty that evening, or The watchman was fired because he was drunk on duty. [Mid-1600s] The antonym, off duty, means “not engaged in one's work,” as in Captain Smith was much more amiable when he was off duty. [Mid-1800s]

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Example Sentences

See Examples For:

on duty

Navy captain who is on duty nearby and gets an unexpected distress signal from the cargo ship, is decisive and strong.

From The Wall Street Journal ● Aug. 20, 2026

"You have to literally stay on duty and stare at the screen the whole time, because you can easily miss it," said Esko, who did not appear to struggle, even late into the night.

From Barron's ● Aug. 16, 2026

Witnesses I spoke with were unanimous on one detail: “Only one of the three officers on duty that night tried to do anything.”

From Slate ● Aug. 11, 2026

Speaking after the attack, Prime Minister Anutin Charnvirakul said he plans to introduce laws that restrict the carrying of firearms in public, with the new legislation only allowing government officials on duty to carry guns.

From BBC ● Aug. 7, 2026

“Beat it,” said the doctor on duty there, who was doing a crossword puzzle.

From "Catch-22" by Joseph Heller