Apophysis \A*poph"y*sis\, n.; pl. {-ses}. [NL., fr. Gr. ? offshoot, process of a bone, fr. ? to grow from; ? from + ?, ?, to grow.] 1. (Anat.) A marked prominence or process on any part of a bone. 2. (Bot.) An enlargement at the top of a pedicel or stem, as seen in certain mosses. --Gray.