I. wag 1 /wæɡ/ BrE AmE verb ( past tense and past participle wagged , present participle wagging )
[ Date: 1200-1300 ; Language: Old English ; Origin: wagian 'to shake' ]
1 . [intransitive and transitive] if a dog wags its tail, or if its tail wags, the dog moves its tail many times from one side to the other
2 . [transitive] to move your finger or head from side to side, especially to show disapproval:
‘You naughty girl!’ Mom said, wagging her finger at me.
⇨ it’s (a case of) the tail wagging the dog at ↑ tail 1 (11), ⇨ set tongues wagging at ↑ tongue 1 (14)
II. wag 2 BrE AmE noun
[ Sense 1: Date: 1500-1600 ; Origin: Perhaps from waghalter 'person likely to be hanged' (16-17 centuries) , from wag + halter 'noose' ]
[ Sense 2: Date: 1500-1600 ; Origin: ⇨ ↑ WAG 1 ]
1 . [countable] old-fashioned someone who says or does something clever and amusing:
Some wag had drawn a face on the wall.
2 . [countable usually singular] a wagging movement