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

The squad will have to remain on call.

From BBC ● 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

It has 40 volunteers who are on call 24/7, and who actively work with local people to prevent crime and increase safety by working with police and other agencies, according to its website.

From BBC ● Apr. 29, 2026

While he worked with Rojas, Battle’s complaint alleges, she required him “to be on call 24/7” and do her personal errands.

From Los Angeles Times ● Mar. 8, 2026

Several months ago the affiliate here in Birmingham asked us to be on call to engage in a nonviolent direct-action program if such were deemed necessary.

From "While the World Watched: A Birmingham Bombing Survivor Comes of Age during the Civil Rights Movement" by Carolyn Maull McKinstry