Noun
tetracube (plural tetracubes)
A polycube composed of four cubes.
Tetracubes Each of the five free tetrominoes has a corresponding tetracube, which is the tetromino extruded by one unit. Source: Internet
J and L are the same tetracube, as are S and Z, because one may be rotated around an axis parallel to the tetromino's plane to form the other. Source: Internet