juvenile /jo̅o̅″vənəl, -vənīl/ [L, juvenus, youthful] , 1. n., a young person; a youth; a child; a youngster. 2. adj., pertaining to, characteristic of, or suitable for a young person; youthful. 3. adj., physiologically underdeveloped or immature. 4. adj., denoting psychological or intellectual immaturity; childish.
