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

U.S. companies spent an estimated $23.5 billion on call and contact center outsourcing in 2025, according to market research firm Precedence Research.

From The Wall Street Journal • Mar. 26, 2026

Perry Lang cooked for Epstein from around 1998 to 2002, during which time he was “basically on call 24/7,” according to a 2021 FBI interview with Lang included in the files.

From Los Angeles Times • Feb. 11, 2026

The psychological counselors were on call twenty-four hours a day.

From "The Secret History" by Donna Tartt

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