(idiomatic) Delayed; postponed; suspended.
This project is on hold until we can get more information.
Waiting on a telephone call.
I have been on hold for 45 minutes listening to a recording about how important my call is to them.
On reserve; being held for someone.
I have a book on hold for me at the library.
Pertaining to a telephone hold state.
Source: en.wiktionary.orgon-hold