The disk of hyaline cartilage between the metaphysis and the epiphysis of an immature long bone that permits the bone to grow longer.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 750 (https://doi.org/10.1515/pac-2015-1202)