epiphysis (i-pif-i-sis) n. (pl. epiphyses)
1. the end of a long bone, which is initially separated by cartilage from the shaft (diaphysis) of the bone and develops separately. It eventually fuses with the diaphysis to form a complete bone.

2. see pineal gland.
—epiphyseal (epi-fiz-iăl) adj.

epiphysis
1. In the limbs and vertebrae of mammals, a cap of bone at the joints; during growth it is separated from the main bone by a cartilaginous plate. It then ossifies separately, the whole fusing when growth ceases. The extent of the fusion can sometimes be used to estimate the age of an animal.

2. See PINEAL BODY.

epiphysis The terminal section of a growing bone (especially a long limb bone) in mammals. It is separated from the bone shaft (diaphysis) by cartilage. New bone is produced on the side of the cartilage facing the diaphysis, while new cartilage is produced on the other side of the cartilage disc. When the bone reaches adult length the epiphysis merges with the diaphysis.