noun: Someone who changes allegiance and joins the opposite side.
The color, and especially the color of clothing, has long symbolized association with a particular cause. For example, soldiers in an army or players in a sports team don a designated color. The idea behind the word turncoat is someone switching allegiances and turning his coat inside out to hide his earlier colors. Earliest documented use: 1567.
“You could almost imagine the little turncoats from the last poster creeping off and taking up residence in another series of photographs downstairs.”
Julius Purcell; Faces That Cannot be Argued Away; Financial Times (London, UK); Jul 18, 2006.
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