In computing, not connected, so that data cannot be transferred, for example, to a printer. The opposite of on line.
1. In reference to a computing device or a program, unable to communicate with or be controlled by a computer.
2. In reference to one or more computers, being disconnected from a network.
3. Colloquially, a reference to moving a discussion between interested parties to a later, more appropriate, time.
4. (Computer sci) Not connected to a computer network
5. (Transportation) Not on a regular route of a transportation system