backstabbing
/ˈbækˌstæbɪŋ/
noun
The action or practice of criticizing someone in a treacherous manner while feigning friendship.
the media world of backstabbing, scheming, and downright malice
duplicity,treachery,betrayal,double-crossing,faithlessness,unfaithfulness,untrustworthiness,infidelity,bad faith,disloyalty,perfidy,perfidiousness,treason,breach of trust,fraud,fraudulence,underhandedness,cheating,dishonesty,deceit,deceitfulness,deception,falseness,stab in the back,back-stabbing,lying,mendacity,trickery,two-facedness
adjective
(of a person) behaving in a backstabbing way.
backstabbing officials protecting their patch with petty politics