wave off

verb4

1. •
   To give a wave of one's hand, or of a flag or wand, so as to signal (someone) to desist or leave.

   • He waved off the approaching truck driver and restarted the apparatus.
2. •
   Of an aircraft carrier landing signal officer, to signal a pilot to go around.
3. •
   Of a referee, to disallow a field goal with the aforementioned hand gesture.
4. •
   To say goodbye to someone with a wave (hand gesture).