Dictionary

To take (a system, etc.) offline; to demote from an active or online state.

Of a system, currently not connected (generally electrically) to a larger network. For example, a power plant which is not connected to the grid, or a computer which is not connected to the Internet or to any other communications service.

Example: I saved the web pages so I could read them later offline.

(by extension) Happening in the physical world (the real world) as opposed to on the internet.

Example: offline dating

While offline; with an offline system.

Outside the current meeting, in a more private setting.