wag (verb) ‘move to and fro, especially with a quick, jerky motion’
The original sense of wag was simply ‘move, be in motion’, and this is found several times in Shakespeare, as when Titus says ‘the Empress never wags / But in her company there is a Moor (Titus Andronicus, V.ii.87) or Hamlet says he will fight with Laertes over Ophelia ‘until my eyelids will no longer wag’ (Hamlet, V.i.263). One of Shakespeare’s uses has stayed as a modern idiom: Jaques’ ‘how the world wags’ (As You Like It, II.vii.23). The word is also a favourite verb of the Host in The Merry Wives of Windsor, who uses it four times in the sense of ‘go off, depart’: ‘Shall we wag?’ (II.i.212), ‘Let us wag, then’ (II.iii.88). A rare use is Leonato’s, in : Bid sorrow wag, cry ‘hem!’ when he should groan’ (Much Ado About Nothing, V.i.16).
David Crystal is a writer, editor, lecturer and broadcaster, and is the co-author of the new Oxford Illustrated Shakespeare Dictionary.