Adjective
1. characteristic of a lack of maturity;
"immature behavior"2. lacking in development;
"immature plans""an unformed character"3. (used of living things especially persons) in an early period of life or development or growth;
"young people"4. not fully developed or mature; not ripe;
"unripe fruit""fried green tomatoes""green wood"5. not yet mature
6. (of birds) not yet having developed feathers;
"a small unfledged sparrow on the window sill"