adolescence /ad′əles″əns/ [L, adolescere, to grow up] , 1. the period in development between the onset of puberty and adulthood. It usually begins between 11 and 13 years of age with the appearance of secondary sex characteristics and spans the teenage years, terminating at 18 to 20 years of age with the completion of the development of the adult form. During this period, the individual undergoes extensive physical, psychological, emotional, and personality changes. 2. the state or quality of being adolescent or youthful. See also postpuberty, prepuberty, psychosexual development, psychosocial development, pubarche.
