Source : Webster's Revised Unabridged Dictionary (1913)

Metapophysis \Met`a*poph"y*sis\, n.; pl. {Metapophyses}. [NL.
   See {Meta-}, and {Apophysis}.] (Anat.)
   A tubercle projecting from the anterior articular processes
   of some vertebr[ae]; a mammillary process.