noun
1. a battleship who's crew mutinied when the tsarist Russia fell
2. a movie made during soviet Russia depicting the mutiny on the battleship Potemkin

adjective
1. a false display of power
2. a pseudo display of control

Fake, not real, a sham.

Comes from a legend of Governor Potemkin of Crimea who supposedly created sham villages (Potemkin Villages) to impress his queen from a distance, but this story has been overal refuted by historians.