From Longman Dictionary of Contemporary Englishwave somebody/something ↔ down phrasal verbTTCSIGN/GESTUREto signal to the driver of a car to stop by waving at themPeople in passing cars tried waving him down. →wave→ See Verb table
Examples from the Corpus
wave down• During these two stagesbrainwave activity slows down.• It came and went in swirlingwaves that rushed down from the ceiling and swallowed her up.• The result is that this type of wave combs material down from the top of the beach giving a net erosive effect.• Some one Glover knew waved him down in the road at the edge of town.• At that moment, a 30-foot wave crashed down on her.• A larger-than - normalwave was racing down on the raft.• The vibration takes the form of an acousticwave travelling down the rod.• Kipwaved his arm down, without looking back. - I want to know what your cause is, man.