Synonyms

on call

Idioms

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.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

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

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

“They’re both on call all night,” he informs us.

From "Leah on the Offbeat" by Becky Albertalli

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023