Definitions of adolescent:

• noun:   a juvenile between the onset of puberty and maturity
• adjective:   in the state of development between puberty and maturity

  Example: "Adolescent boys and girls"

• adjective:   displaying or suggesting a lack of maturity

  Example: "Adolescent insecurity"

• adjective:   being of the age 13 through 19
• adjective:   relating to or peculiar to or suggestive of an adolescent

  Example: "Adolescent problems"