one-armed bandit
A slot machine designed for gambling in which you pull down a lever on one side that generates a random combination of three shapes, which may or may not award the player money depending on the combination received. After my wife lost her entire month's wages to the one-armed bandits in Atlantic City, we've decided to stay away from casinos altogether.
one-armed bandit
A slot machine, as in It's amazing how many people think they can make money playing a one-armed bandit. This term refers to both appearance and function: the operating lever looks like an arm, and the machine in effect robs players, since it "wins" and keeps the player's money in an overwhelming majority of instances. [c. 1930]