\Am`phis*b[ae]"na\, n. [L., fr. Gr. ?; ? on both
ends + ? to go.]
1. A fabled serpent with a head at each end, moving either
   way. --Milton.
2. (Zo["o]l.) A genus of harmless lizards, serpentlike in
   form, without legs, and with both ends so much alike that
   they appear to have a head at each, and ability to move
   either way. See Illustration in Appendix.
Note: The {Gordius aquaticus}, or hairworm, has been called
      an {amphisb[ae]na}; but it belongs among the worms.