wag (1) — ODE

wag1 /waɡ

▸ verb

( wags, wagging, wagged)

(especially with reference to an animal's tail) move or cause to move rapidly to and fro:

[no object] his tail began to wag

[with object] the dog went out, wagging its tail.

▪ [with object] move (an upwards-pointing finger) from side to side to signify disapproval:

she wagged a finger at Elinor.

▸ noun a single rapid movement from side to side:

a chirpy wag of the head.

– PHRASES

how the world wags dated
how affairs are going or being conducted:

there is no very good theory of how the world wags these days.

tongues wag
used to convey that people are gossiping about someone or something:

this is a small island and tongues are beginning to wag.

– ORIGIN Middle English (as a verb): from the Germanic base of Old English wagian ‘to sway’.