Wag is defined as to move a body part quickly back and forth or up and down over and over again.(verb)
See wag in Webster's New World College Dictionary
Origin: ME waggen, prob. < ON vaga, to move back and forth, rock, akin to OE wagian, to shake, totter < IE base *weĝh-, to move > L vehere, to carry
Origin: prob. short for obs. waghalter, a gallows bird, applied to a joker, rogue (< ? wag + halter)
See wag in American Heritage Dictionary 4
verb wagged wagged, wag·ging, wags verb, intransitive
Origin: Middle English waggen; see wegh- in Indo-European roots.
Origin: Perhaps from wag1.
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