Backbiting
From BiblePortal Wikipedia
King James Dictionary [1]
BACK'BITING, n. The act of slandering the absent secret calumny. 2Cor.xii.
Webster's Dictionary [2]
(n.) Secret slander; detraction.
Charles Buck Theological Dictionary [3]
See Detraction and SLANDER.
Hastings' Dictionary of the New Testament [4]
See Evil-speaking.