There are multiple definitions - click on the translation that matches your context.

Abruf

Substantiv

partial

on-call employment

Comparative law notes

Under employment law in the United States, this arrangement is used by businesses that cannot always be sure how many people they'll need for a given shift. Putting employees "on call" is the solution; i.e., have the staff members wait by the phone or in the break room, only working if the business needs them.