from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Not under the control of a central computer, as in a manufacturing process or experiment.
- adj. Not connected to a computer or computer network.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. 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.
- adj. Happening in the physical world (the real world) as opposed to on the internet.
- adv. While offline; with an offline system.
- adv. Outside the current meeting, in a more private setting.
off + line (Wiktionary)