The Collaborative International Dictionary of English v.0.48:

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]

The Collaborative International Dictionary of English v.0.48:

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]

WordNet (r) 3.0 (2006):

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]