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

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

From Los Angeles Times • Jun. 9, 2026

And the bench of venture-backed AI roll-up companies has expanded in recent years to include companies like London-based Dwelly, which acquires property-management companies, and San Francisco-based Crescendo, which focuses on call centers.

From The Wall Street Journal • Jun. 9, 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

The team of specialists is on call 24 hours a day to collect the most poorly children and babies and take them to intensive care, supporting 27 hospitals across the south of England.

From BBC • Mar. 4, 2026

—Sir, Dr. Carrothers was the doctor on call tonight, but as I told you, he had a sudden emergency.

From "Tears of a Tiger" by Sharon M. Draper