[kawl-in]Radio and Television.
a program in which listeners or viewers phone in comments or questions to the host or a person being interviewed.
a live telephone conversation intended for broadcasting between a program's host and a person being interviewed.
of, relating to, or featuring such phone calls or conversations: a call-in program.
Origin of call-in
First recorded in 1960–65; noun use of verb phrase call in
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019