The Collaborative International Dictionary of English v.0.48:

Preaxial \Pre*ax"i*al\, a. (Anat.)
   Situated in front of any transverse axis in the body of an
   animal; anterior; cephalic; esp., in front, or on the
   anterior, or cephalic (that is, radial or tibial) side of the
   axis of a limb.
   [1913 Webster]