What is the meaning of turn·coat (tûrnkt)?

n.
* One who traitorously switches allegiance.

* a person who deserts one cause or party for the opposite faction; renegade

* a disloyal person who betrays or deserts his cause or religion or political party or friend etc.

Synonyms: traitor, renegade, defector, seceder, deserter, apostate, backslider, recreant