"Physical maturity" refers to the stage when a person's body has fully developed and attained its maximum growth potential, such as reaching the adult height and the ability to reproduce. Full definition
The adolescent period typically begins around six months of age, and will be over when a dog reaches physical maturity around two to three years old. (whole-dog-journal.com)
Kids mature at their own pace and develop their unique skills at different times, so consider your child's emotional and physical maturity before you commit to a season of sports. (kidshealth.org)
By the beginning of this developmental period small to medium breed puppies will likely have reached their full height, and simply be gaining weight as they head towards physical maturity. (raisingrascal.com)