dimorphous

from WordNet (r) 3.0 (2006)

dimorphous
    adj 1: occurring or existing in two different forms; "dimorphic
           crystals"; "dimorphous organisms" [syn: {dimorphic},
           {dimorphous}]

from The Collaborative International Dictionary of English v.0.48

Dimorphous \Di*mor"phous\, a. [Cf. F. dimorphe.]
   1. (Biol.) Characterized by dimorphism; occurring under two
      distinct forms, not dependent on sex; dimorphic.
      [1913 Webster]

   2. (Crystallog.) Crystallizing under two forms fundamentally
      different, while having the same chemical composition.
      [1913 Webster]