a·dult 
(ə-dŭlt, ădŭlt)
(ə-dŭlt, ădŭlt)n.
1. One who has attained maturity or legal age.
2. Biology A fully grown, mature organism.
adj.
1. Fully developed and mature.
2. Relating to, intended for, or befitting adults: adult education.
3. Containing or dealing in explicitly sexual material; pornographic: adult movies.
[From Latin adultus, past participle of adolēscere, to grow up; see ADOLESCENT.]
a·dulthood′ n.
a·dultness n.