1. To become active or begin operating. We've had the building finished for days now, but we're still waiting for the power to come online. Hundreds of new factories are slated to come online over the next year, which will bring a much-needed boost to the economy.

2. To log onto the Internet, usually meaning some social communication service thereof. I'm just waiting for my dad to come online, I haven't spoken to him in weeks!

1. To become active or begin operating. Hundreds of new factories are slated to go online over the next year, which will bring a much-needed boost to the economy.

2. To log onto and use the Internet. I'm going online to see what movies are showing tonight.

1. Connected to the internet or a local network, as on a computer, smartphone, video game console, etc. You've been online for far too long today. Put your shoes on and go play outside. Once the new server is online, the website should be able to load about three times faster.

2. Describing any activity done over the Internet. Online dating is the new normal when it comes to meeting people. It's interesting to see how online communication really adds to our lexicon.