cubic

Concise Oxford English Dictionary © 2008 Oxford University Press:
cubic /ˈkjuːbɪk/

▶adjective

• 1 having the shape of a cube.

  ■ denoting a crystal system with three equal axes at right angles.

• 2 denoting a unit of measurement equal to the volume of a cube whose side is one of the linear unit specified: a cubic metre.

• 3 Mathematics involving the cube (and no higher power) of a quantity or variable.

– derivatives
cubical adjective,
cubically adverb.