What is the meaning of Thimblerig?

A game of skill which requires the bettor to guess under which of three small cups (or thimbles) a pea-sized object has been placed after the party operating the game rapidly rearranges them, providing opportunity for sleight-of-hand trickery; a shell game.

One operating such a game.

To cheat in the thimblerig game.

To cheat (someone) by trickery.

Source: wiktionary.org