Definition for Metaphysis
From Biology Forums Dictionary
The metaphysis is the wider portion of a long bone adjacent to the epiphyseal plate. This is this part of the bone that grows during childhood; as it grows, it ossifies near the diaphysis and the epiphyses. At roughly 18 to 25 years of age, the metaphysis stops growing altogether and completely ossifies into solid bone.
Epiphyseal plates ("growth plates") are located in the metaphysis[citation needed] and are responsible for growth in the length of the bone.