cubic

Cubic means shaped like a cube, or measured in three dimensions. Length times width times height.

The measuring sense is the one you meet most: cubic metres of concrete, cubic feet of storage, the cubic capacity of an engine. It is how volume is expressed, and it is worth keeping apart from square, which measures area across two dimensions only. In maths, a cubic equation is one where the highest power is three. Crystals get the word too, since a cubic crystal is built on right angles all the way through.