| noun | a young person, not fully developed |
| adjective | of or relating to or characteristic of or appropriate for children or young people “juvenile diabetes” |
| adjective | displaying or suggesting a lack of maturity “adolescent insecurity” |
| juvenile | adjective | of or relating to or characteristic of or appropriate for children or young people |
| juvenile | noun | a young person, not fully developed |
| juvenility | noun | the freshness and vitality characteristic of a young person |
| jejuneness | noun | lacking and evidencing lack of experience of life |
| jejunity | noun | the quality of being vapid and unsophisticated |
| puerility | noun | the state of a child between infancy and adolescence |