tongues wag - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
People are gossiping. For example, Tongues wagged when another police car was parked in front of their house, or Their arrival in a stretch limousine set the neighbors' tongues wagging. This metaphoric expression transfers the rapid movement of the tongue to idle or indiscreet chatter. [Late 1500s]