a.  1.  Having the form or properties of a cube; contained, or capable of being contained, in a cube.  
2.  (Crystallog.) Isometric or monometric;
 
n.  1.  (Geom.) A curve of the third degree.

Adj.  1.  cubic  having three dimensions Synonyms: threedimensional Antonyms: linear, onedimensional  of or in or along or relating to a line; involving a single dimension; "a linear foot" planar, twodimensional  involving two dimensions 