IMMATURE

Definition

1. adjective characteristic of a lack of maturity.
2. adjective (used of living things especially persons) in an early period of life or development or growth. — synonyms: young
3. adjective not fully developed or mature. — synonyms: green, unripe, unripened
4. adjective not yet mature.
5. adjective (of birds) not yet having developed feathers. — synonyms: unfledged