tip off verb 5tip-off noun 3forms 4 verb5 •To alert or inform (someone), especially confidentially.An anonymous caller tipped off the police that the suspect would be in the area.Someone must have tipped him off. [A likely explanation for why he has disappeared.] •To put the ball in play by throwing it up between two opponents. •To begin.The game tips off in an hour, so hurry back! •To use a particular brush technique for producing a flawless surface on a wet coat of paint. •(no longer used) To pour out (liquor); to tip the vessel and drink until it is empty. tip-off noun3 •A report of suspicious behaviour, especially to an authority.The police received a tip-off about a recent bank robbery. •An obvious clue or indication.The broken window and overturned plant pots were a tip-off that something was wrong. •Jump ball that starts a game. formstipped off · tipping off · tips off · tip-offs