The Collaborative International Dictionary of English v.0.48:
Rhombic \Rhom"bic\ (r[o^]m"b[i^]k), a. 1. Shaped like a rhomb. [1913 Webster] 2. (Crystallog.) Same as Orthorhombic. [1913 Webster]WordNet (r) 3.0 (2006):
rhombic adj 1: resembling a rhombus