back-stabbing

back-stabbing ▶noun [ mass noun ] the action of criticizing someone in a treacherous manner despite pretending friendship with them: the media world of back-stabbing, scheming, and downright malice. ▶adjective (of a person ) engaging in back-stabbing; critical of other people despite pretending friendship with them: back-stabbing officials protecting their patch with petty politics. DERIVATIVES back-stabber noun