ad·o·les·cence 
(ăd′l-ĕsəns)
(ăd′l-ĕsəns)n.
1. The period of physical and psychological development from the onset of puberty to adulthood.
2. A similar period in nonhuman animals, ending at sexual maturity.
3. A transitional period of development between an initial or early phase and an established or mature phase: the adolescence of a nation.