v.1. To go away: The children all went off to play at the park. Don't go off mad—let me explain!
2. To stop functioning. Used especially of electrical devices: The lights went off suddenly, and the performance began right away.
3. To occur, or be perceived as having occurred, in some particular manner: I think our party went off very well!
4. To adhere to the expected course of events or the expected plan: The project went off smoothly.
5. To stop taking some drug or medication: She went off painkillers a few weeks after the operation.
6. To make a noise; sound: The siren goes off every day at noon.
7. To undergo detonation; explode: If you push this red button, the bomb will go off.
8. go off on To begin to talk extensively about something: He went off on a series of excuses for his bad behavior.
9. go off on To berate someone directly and loudly: My boss really went off on me when she learned that I had forgotten to make the phone call.