wag

verb

1. (ambitransitive)To swing from side to side, as an animal's tail, or someone's head to express disagreement or disbelief.

   “No discerner durst wag his tongue in censure.”

   “Every one that passeth thereby shall be astonished, and wag his head.”

   “Carrados wagged his head in good-humoured resignation.”

2. (Australia, New-Zealand, UK, slang)To play truant from school.

   “"My misfortunes all began in wagging, Sir; but what could I do, exceptin' wag?" "Excepting what?" said Mr. Carker. "Wag, Sir. Wagging from school." "Do you mean pretending to go there, and not going?" said Mr. Carker. "Yes, Sir, that's wagging, Sir."”

   “They had "wagged it" from school, as they termed it, which..meant truancy in all its forms.”

   “[…] she wagged English and Science just to go in his car […]”

3. (intransitive, obsolete)To go; to proceed; to move; to progress.

   “"Thus we may see," quoth he, "how the world wags."”

4. To move continually, especially in gossip; said of the tongue.

   “She's a real gossip: her tongue is always wagging.”

5. (intransitive, obsolete)To leave; to depart.

   “I will provoke him to 't, or let him wag.”

6. (intransitive, slang)Of the tail (lower order of the batting lineup): to score more runs than expected.

   “The tail wagged.”

noun

1. An oscillating movement.

   “The wag of my dog's tail expresses happiness.”

2. A witty person.

   “Was not my Lord The veryer Wag o'th' two?”

   “But being a bit of a wag, and relishing a good joke amazingly, he concluded to have a little fun, and at the same time learn his friend a lesson concerning his negligent custom.”

   ““A nice, juicy steak,” he is said to have called for, “French fries, apple pie and a cup of coffee.” It is probable that he really said “a coff of cuppee,” however, as he was a wag of the first water and loved a joke as well as the next king.”

   “By Wednesday it had already won art-world notoriety, and on Saturday it achieved a public visibility that any artist would envy, after a self-promoting wag tore the banana off the wall and gobbled it up.”

   “Many people can't work from home - as one wag observed: "Well, I would, but the wife doesn't like me laying tarmac in the front room!"”

3. (Ireland, informal)A wife or girlfriend of a sports star or other celebrity, originally and especially of an association football player.

   “The World Cup WAGs are a good example of this. The younger girls, nicknamed the ‘hen-night crowd’ and led by Colleen McLoughlin, dance on tables and drink until the early hours while No. 1 WAG Victoria Beckham remains aloof, dining sedately with Ashley Cole’s fiancee, Cheryl Tweedy.”

   “In Wimbledon, the tennis WAGs and - just as excitingly - HABs (Husbands and Boyfriends) have been appearing courtside, enthusiastically cheering on their beloved other halves with a degree of style.”

   “They looked her up online and soon began following Ms. Riddle on social media, where she shares her life as a tennis WAG — an acronym for “wives and girlfriends,” popularized in Britain in the mid-2000s to describe, disparagingly, a group of preening, partying women attached to soccer players.”

   “WAGs have taken on a second life in the American sports world, linked to basketball, football and, more recently, Formula 1 and tennis.”

4. (US, abbreviation, acronym, alt-of, informal, slang)Acronym of wild-assed guess; a rough estimate.
5. (abbreviation, acronym, alt-of)Acronym of women's artistic gymnastics.