flackern

From Middle High German vlackern, perhaps ultimately imitative of birds' wings, or from Proto-Germanic *flakuraz (“shaking, wavering”), related to *flakurōną (“to roam, wander”), from Proto-Indo-European *plag- (“to roam, wander”), from Proto-Indo-European *pelə- (“to wander”). Or, from Proto-Germanic *fleuganą (“to fly”). From flacken + -ern (iterative suffix) See also West Frisian flikkerje, Middle Low German vlickeren (“to beat, flap”), Old English flicorian (“to flap, flutter”). More at English flicker, flaunt.