WAVE v. (no obj.) move one’s hand, or other appendage, to and fro in greeting. (ORIGIN) old English: wafian.
Landrover wave: (mainly UK): the restrained elevation of one finger above the steering wheel.
Motorbike wave: (mainly European): elevation of left leather clad leg from gear peg, extended only to other bikers in greeting and cyclists in sympathy.
Two finger wave: (mainly Anglo-Saxon, Europe, North America): extended by vehicle operators to any incumbent who might have delayed them for a nanosecond, and by incumbent to departing vehicle for a lack of courtesy, respect for road space, or their red necks.
(with obj.) Maté Wave: (Uruguayan): Full elevated hand movement, with it’s attached bombilla, sometimes preceded with a headlight flash and hoot on the horn.