epiphysis
noun
epiph·y·sis i-ˈpi-fə-səs 
plural epiphyses i-ˈpi-fə-ˌsēz
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
Example Sentences
Recent Examples on the Web Meanwhile, the epiphyses on the ischium and the ends of the femur and shin bone (tibia) were well-developed but hadn’t yet fused—in other words, DH7 wasn’t a very young child but was definitely still growing. 
Kiona N. Smith, Ars Technica, 10 Apr. 2020 Vidyadhar Upasani, a pediatric orthopedist at Rady Children’s Hospital in San Diego, uses 3-D printing to help plan intricate bone procedures to treat, for example, slipped capital femoral epiphysis, the most common hip disorder in adolescents. Erin Blakemore, Washington Post, 11 June 2018
Kiona N. Smith, Ars Technica, 10 Apr. 2020 Vidyadhar Upasani, a pediatric orthopedist at Rady Children’s Hospital in San Diego, uses 3-D printing to help plan intricate bone procedures to treat, for example, slipped capital femoral epiphysis, the most common hip disorder in adolescents. Erin Blakemore, Washington Post, 11 June 2018 Word History
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
First Known Use
1634, in the meaning defined at sense 1
Medical Definition
epiphysis
noun
epiph·y·sis i-ˈpif-ə-səs
plural epiphyses -ˌsēz
1
: a part or process of a bone that ossifies separately and later becomes ankylosed to the main part of the bone
especially : the usually rounded end of the shaft of a long bone that is composed mainly of cancellous bone covered by a thin layer of compact bone compare diaphysis
2
: pineal gland