The Collaborative International Dictionary of English v.0.48:

Cubiform \Cu"bi*form\ (k?"b?-f?rm), a.
   Of the form of a cube.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cubiform
    adj 1: shaped like a cube [syn: cubelike, cube-shaped,
           cubical, cubiform, cuboid, cuboidal]