1. A person growing up from childhood to adulthood, especially one from about 12 to about 20 years of age; youth, teenager, teen, minor: Over 70 percent of today’s adolescents are expected to finish high school.
2. Teenager, juvenile: The presentations of many movies about life is primarily geared to adolescents.

The words adolescent and "adult" come from different forms of the Latin verb adolescere, "to grow up", and in Latin they mean “growing up” and “grown-up”, respectively.

1. Referring to the stage of development between childhood and maturity: Jim was in the adolescent phase of life of no longer being a child, but who had not yet reached adulthood.
2. Concerning the behavior of a young person: Jack seemed to be very adolescent and immature because he was so silly in one moment and then crying in the next..
3. Etymology: from Latin adolescent from adolescere, "to be nourished, to grow up". This is also the source of English adult from alere, "to nourish".

The physiological and emotional changes which occur during teenage years and constitute a sudden demand on the ego for any unusual adaptational responses.