epiphysis

epiphysis
    n 1: the end of a long bone; initially separated from the main
         bone by a layer of cartilage that eventually ossifies so
         the parts become fused
    2: a small endocrine gland in the brain; situated beneath the
       back part of the corpus callosum; secretes melatonin [syn:
       {pineal gland}, {pineal body}, {epiphysis cerebri},
       {epiphysis}]
    

Pineal \Pi"ne*al\, a. [L. pinea the cone of a pine, from pineus
   of the pine, from pinus a pine: cf. F. pin['e]ale.]
   Of or pertaining to a pine cone; resembling a pine cone.
   [1913 Webster]

   {Pineal gland} (Anat.), a glandlike body in the roof of the
      third ventricle of the vertebrate brain; -- called also
      {pineal body}, {epiphysis}, {conarium}. In some animals it
      is connected with a rudimentary eye, the so-called pineal
      eye, and in other animals it is supposed to be the remnant
      of a dorsal median eye.
      [1913 Webster]
    

Epiphysis \E*piph"y*sis\, n.; pl. {Epiphyses}. [NL., fr. Gr.
   'epi`fysis, fr. 'epify`ein to grow upon; 'epi` upon + fy`ein
   to grow.] (Anat.)
   (a) The end, or other superficial part, of a bone, which
       ossifies separately from the central portion, or
       {diaphysis}.
   (b) The cerebral epiphysis, or pineal gland. See {Pineal
       gland}, under {Pineal}.
       [1913 Webster]