Backstabber

Part of speech: noun

Pronunciation: /ˈbækˌstæbɚ/

Definitions

1. An individual who secretly betrays a companion's trust while appearing to be supportive
2. A person who undermines a friend's interests through hidden malice while feigning loyalty
3. A deceitful individual who pretends to support others while secretly betraying their confidence and interests

Etymology: "Backstabber" is a plain compound: "back" joined to "stabber," someone who stabs. The image of a knife in the back, struck by a person who was supposed to be an ally, gives the noun its sense of a secret, treacherous betrayer. The metaphor does the work here; nothing about the word's construction needs a special story. The compound itself is transparent, so its interest lies in the picture it paints. Stabbing someone in the back is cowardly because the victim cannot see the blow coming, and the word carries that sense of ambush and concealment. That is why it describes a person who undermines a colleague or friend while appearing loyal to their face.

Synonyms: traitor, betrayer, double-crosser, deceiver, turncoat

Antonyms: loyalist, supporter, ally, friend, advocate