on call

Idioms  

1. Available if summoned, as in Medical residents are required to be on call at least three nights a week. This expression originated as at call in the late 1500s. Also see at someone's beck and call.

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Example Sentences

See Examples For:

on call

Nevertheless, the assistants were on call 24/7, Anya says.

From BBC ● Jul. 18, 2026

California requires that a veterinarian to be present or nearby and on call.

From Los Angeles Times ● Jun. 9, 2026

She’s on call for emergencies at all times.

From The Wall Street Journal ● May 13, 2026

Having a good contractor on call is now a must-have for companies building power plants, and they are willing to pay up for them.

From Barron's ● May 4, 2026

There wasn’t much crime to deal with, but he was always on call to come help housewives move furniture, and anybody who needed a ride could depend on Tag to supply taxi service.

From "October Sky" by Homer Hickam