Dictionary
bad-mouth
Pronunciation: (bad'mouth" or, sometimes, -mou&thslash;"), [key]—
v.t., -mouthed, -mouth•ing.
Slang.to speak critically and often disloyally of; disparage:
Why do you bad-mouth your family so much? Also,bad'mouth".Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.