Definitions
1.verbTo bring (a system, etc.) online; to promote to an active or running state.
2.adjectiveOf a system: connected (generally electrically) to a larger network.
3.adjectiveAvailable over, or delivered from, the Internet."I prefer to read online newspapers."
4.adjectiveConnected to the Internet."I'll be online tonight, so I'll be able to reply to your email."
5.adjectiveAvailable on a computer system, even if not networked."Press the F1 key to access the online help."
6.adjectiveOf a system: active, particularly building facilities (such as power) or a factory or power plant."Once this factory comes online, it will double car production in our country!"
7.adverbWhile online; while in a running or active state, or connected to the Internet."He works online."