on-call adjective 1on call prepositional phrase 1 adjective[before a noun]1 •on callThe traditional way of dealing with these events was for an on-call traffic manager to review (with the engineering functions) the likely time normal working could be resumed. — 2019 on call prepositional phrase1 •Available to be summoned.He spent the weekend on call and couldn't fully relax.Get the surgeon on call in here right now!
