The Collaborative International Dictionary of English v.0.48:

dicephalous \di*ceph"a*lous\ (d[-i]*s[e^]f"[.a]*l[u^]s), a. [Gr.
   dike`falos; di- = di`s- twice + kefalh` head.]
   Having two heads on one body; double-headed.
   [1913 Webster]