wag: [13] Wag was derived from the Middle English descendant of Old English wagian ‘totter’, a word related to English wave of the sea. Waggle [15] was based on it. The noun wag ‘comical fellow’, first recorded in the 16th century, is generally taken to be short for waghalter, literally ‘someone who swings to and fro in a noose’, hence ‘someone destined for the gallows’. => waggle
