The origin of words: WAG

Wag, meaning ‘to waver or vasillate,’ or ‘to lack steadfastness,’ dates back to the late 12th or early 13th century, as the Middle English waggen. It probably came partly from a Scandinavian source, and partly from the Old English waggian (to move backwards and forwards). It can be traced back to the Proto-Germanic root wag– and the Proto-Indo-European root wegh– (to go, move, or transport in a vehicle). It is related to the Old Norse vagga (a cradle), the Danishvugge (to rock a cradle) and the Old Swedish wagga (to fluctuate, or to rock a cradle), as well as the Old High German weggen and Gothic wagjan (both meaning ‘to wag’). The transitive sense, ‘to move something back and forth,’ dates back to around the year 1300, and dogs have been said to wag their tails since the mid-15th century. The noun wag, meaning ‘the act of wagging,’ dates back to the late 16th century, but the noun wag, meaning ‘a person who makes jokes’ is slightly older (mid-16th century). Some linguists think it was originally a short form of waghalter, which meant ‘gallows bird’ (a person destined to swing from the gallows for committing a crime), though others think it comes directly from the verb, and point to the noun wagger (someone who agitates or stirs up trouble) as proof.