Each piece in Tetris is called a tetris.

The answer is false because each individual piece in Tetris is not called a "Tetris." Instead, these pieces are referred to as tetrominoes. Tetris is the name of the overall puzzle game, whereas tetrominoes are the various geometric shapes that players manipulate and place onto the game board to clear lines. Each tetromino consists of four connected squares, and they are the essential building blocks of the gameplay in Tetris.