The french wave

A dismissive hand gesture that waves a person away, often impatiently or irritatedly. It is frequently made while not even looking at the person, who is usually someone who unwelcomely interrupted the conversation or activities of the person giving the french wave. A normal wave involves mostly motion of the arms and wrist pivoting from left to right; the french wave mostly involves motion of the fingers (which are held together) back and forth as though to say "shoo."

I tried to talk to him while he was watching soccer, and he gave me the french wave.