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

Campus police had six officers on duty at the event, approximately one-quarter of the full force, and local police weren’t on site, according to court records.

From The Wall Street Journal ● Sep. 16, 2026

It said an inexperienced third officer was at the helm and there was no lookout on duty, describing it as "serious negligence".

From Barron's ● Sep. 3, 2026

Across the weekend, more than 3,000 stewards were on duty, double the usual number, and more than 7,000 Metropolitan Police officers were deployed to west London.

From BBC ● Aug. 31, 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

Dora insisted that a skeleton crew remain on duty to take care of the regulars.

From "Cannery Row" by John Steinbeck