juvenile, juvenile person -- (a young person, not fully developed)
Overview of adj juvenile
The adj juvenile has 2 senses
juvenile -- (of or relating to or characteristic of or appropriate for children or young people; "juvenile diabetes"; "juvenile fashions")
adolescent, jejune, juvenile, puerile -- (displaying or suggesting a lack of maturity; "adolescent insecurity"; "jejune responses to our problems"; "their behavior was juvenile"; "puerile jokes")