immature
adj
1 not sensible in behaviour or in controlling one's feelings; less mature than one would expect (行為或控制感情)不成熟的, 不夠老練的
He's very immature for his age. 就他的年齡來說, 他還很不成熟.
2 not (yet) fully developed or grown (尚)未充分成長的; 發育(尚)未完全的
immature plants 幼嫩的植物.