In math, a cube is a number multiplied by itself three times. The cube of 2 is 8 (2 x 2 x 2). It is also a three-dimensional shape where each of the six sides is a square or something shaped like a cube, such as an ice cube or meat cut into cubes).
The noun cube goes back to the Greek word kybos, which was a six-sided die used in games. As a verb, cube means to cut into cube shapes. You can buy cookie dough that is ready for baking and formed into cubes. Place each cube on the cookie sheet, and the dough becomes a dozen round cookies — or fewer if you pop a cookie dough cube into your mouth before baking!