Definition of postaxial in US English:

postaxial

adjective

Anatomy
  • Located posterior to an axis, especially the main axis of the body or of a body part; specifically designating, relating to, or derived from the lower (caudal) border of a developing limb; ulnar or fibular. Opposed to preaxial.

Origin

Late 19th century; earliest use found in St. George Mivart (1827–1900), zoologist and Roman Catholic polemicist. From post- + axial.

Pronunciation

postaxial

/ˌpəʊstˈaksɪəl/