1) Ade 2) Cardinal numbers 3) Youth 1) HS students 2) SE Hinton readers, often 3) Acne time 4) Acne years 5) Acne years, for many 6) Adolescence 7) Adolescent period 8) Adolescent times 9) Adolescent years 10) Adolescents 11) Adult wannabes 12) After-12 period 13) After-school jobholders 14) Age group 15) Age of growing up 16) Ages 13-19 
• (n. pl.) The years of one`s age having the termination -teen, beginning with thirteen and ending with nineteen; as, a girl in her teens.
the years 13 to 19 in the human life span, a period roughly equivalent to adolescence (q.v.).
Teens noun plural [ See Ten .] The years of one's age having the termination -teen , beginning with thirteen and ending with nineteen; as, a girl in her teens . 
[n] - the time of life between the ages of 12 and 20 2. [n] - all the numbers that end in -teen
The worst of the teenage spots should be disappearing and your skin is plump and glowing. Investing time in your skin and moisturising with SPF15 will pay dividends as you age.
noun all the numbers that end in -teen