Definition: The term "unmatured" is a medical term used to describe a condition where a child's body has not yet reached sexual maturity. This can occur in males and females, but it is more common in males. Males who are unmedicated or do not receive their hormones at the right time may experience this condition. The hormone testosterone plays an important role in development and growth during puberty, which occurs between ages 10-13 years for boys and 8-9