behind someone's back


Out of one's presence or without someone's knowledge, as in Joan has a nasty way of maligning her friends behind their backs. Sir Thomas Malory used this metaphoric term in Le Morte d'Arthur (c. 1470): “To say of me wrong or shame behind my back.” [Early 1300s]

Words Nearby behind someone's back

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.