1.Definition: being of the age 13 through 19

Related Adjective(s):teen, teenage, teenaged

2.Definition: displaying or suggesting a lack of maturity

"Adolescent insecurity"

Related Adjective(s):jejune, juvenile, puerile

3.Definition: in the state of development between puberty and maturity

"Adolescent boys and girls"

4.Definition: relating to or peculiar to or suggestive of an adolescent

"Adolescent problems"