adj.1. a. Having the shape of a cube.
b. Shaped similar to a cube.
2. a. Having three dimensions.
b. Abbr. c or cu. Having a volume equal to a cube whose edge is of a stated length: a cubic foot.
3. Mathematics Of the third power, order, or degree.
4. Of or relating to a crystalline form that has three equal axes at right angles to each other; isometric.