Merriam-Webster Collegiate Dictionary - epiphysis

 noun  (plural epiphyses)  Etymology: New Latin, from Greek, growth, from epiphyesthai to grow on, from epi- + phyesthai to grow, middle voice of phyein to bring forth — more at be  Date: 1634  1. a part or process of a bone that ossifies separately and later becomes ankylosed to the main part of the bone; especially an end of a long bone  2. pineal gland