ad·o·les·cent [àdd? léss’nt] noun (plural ad·o·les·cents) somebody in period preceding adulthood: somebody who has reached puberty but is not yet an adult adjective 1. experiencing adolescence: going through the period of adolescence adolescent males 2. happening during adolescence: typically occurring during the period of adolescence 3. immature: involving, relating to, or meant for somebody who is immature [15th century. Via French < Latin adolescent-, present participle of adolescere "be nourished, grow up" < alere "nourish"]