recall, request to return; demand repayment of a debt; phone to one's job and ask for permission to stay at home due to illness (Slang)
If you call in somewhere, you make a short visit there. He just calls in occasionally I got into the habit of calling in on Gloria on my way home. = drop in
A call-in is a programme on radio or television in which people telephone with questions or opinions and their calls are broadcast. a call-in show on Los Angeles radio station KABC. a radio or television programme in which people telephone to give their opinions British Equivalent: phone-in
a telephone call to a radio station or a television station in which the caller participates in the on-going program