Wiktionary
wave off
vb. 1 (context transitive English) To say goodbye to someone with a wave (hand gesture) 2 (context basketball English) Of a referee, to disallow a field goal with the aforementioned hand gesture.
WordNet
wave off
v. dismiss as insignificant; "He waved off suggestions of impropriety"
Usage examples of "wave off".
She nearly made it on the first try but was blown off course by the effect of the sails at the last moment and banked off as Vickie gave her a wave off.
Nylan raised a hand to wave off the question, but realized that Ryba couldn't see the gesture.