immature

adjective
1
behaving in a way that is not sensible and is typical of people who are much younger
ناپخته, کودکانه, نابالغ, خام
2
not fully developed or grown
نابالغ, ناپخته, نارس, خام
immature plants
The immature birds have shorter tails and brown, speckled plumage.
opposite mature