teenager       
noun [ C ] uk/ˈtiːnˌeɪ.dʒər/ us/ˈtiːnˌeɪ.dʒɚ/ (informal teen)
A2 (13岁至19岁的)青少年
a young person between 13 and 19 years old
  The magazine is aimed at teenagers and young adults. 这份杂志的读者对象是青少年和二十来岁的年轻人。 
 - More examples
 - He was a bit of a rebel when he was a teenager and dyed his hair pink and had his nose pierced.
 - As a teenager, Clare was always getting on the wrong side of her mother.
 - Many parents find it hard to relate to their children when they are teenagers.
 - He found it very hard teaching a class full of stroppy teenagers.
 - It's pathetic to see 50-year-old rock stars prancing around on stage as if they were still teenagers.