diapophysis

from The Collaborative International Dictionary of English v.0.48

Diapophysis \Di`a*poph"y*sis\, n. [NL. See {Dia-}, and
   {Apophysis}.] (Anat.)
   The dorsal transverse, or tubercular, process of a vertebra.
   See {Vertebra}.
   [1913 Webster]