secret information that somebody gives, for example to the police, to warn them about an illegal activity that is going to happen or has happened
Example:
- The man was arrested after an anonymous tip-off.
- Customs officers had received a tip-off about a shipment of cocaine.
- He was arrested after a tip-off to police.
the start of a game of basketball, when the ball is thrown up in the air between two opponents
Example:
- The Lions quickly gained possession of the ball at tip-off.