NOUN (2)

1. the time period between the beginning of puberty and adulthood;

2. in the state that someone is in between puberty and adulthood;

The Collaborative International Dictionary of English v.0.48:

Adolescence \Ad`o*les"cence\, n. [Fr., fr. L. adolescentia.]
   The state of growing up from childhood to manhood or
   womanhood; youth, or the period of life between puberty and
   maturity, generally considered to be, in the male sex, from
   fourteen to twenty-one. Sometimes used with reference to the
   lower animals.
   [1913 Webster]