pueriledisapproving
disapproving
not having much experience of something: 没经验的
politically immature政治上不成熟
biology specialized
not yet completely grown or developed: 未长成的，发育未全的
While the animals are still immature, they do not breed.动物发育未全时不会生育。
SMART Vocabulary: related words and phrases Physically and mentally mature & immature
adult
adulting
ageing
babyish
childish
immaturely
immaturity
infantile
juvenile
make a man (out) of someoneidiom
mature
maturity
petulance
petulancy
petulant
petulantly
post-adolescent
secondary sexual characteristic
sophomoric
young at heartidiom
Related word
immaturity
immature | American Dictionary
immature
adjective
us/ˌɪm·əˈtʃʊər, -ˈtʊər/
not completely developed physically, mentally, or emotionally, or lacking the expected type of responsible behavior for your age:
Some of the boys in my class are so immature – they’re always doing silly things.
immaturity
noun[ U ]us/ˌɪm·əˈtʃʊər·ɪ·t̬i, -ˈtʊər-/
physical/emotional immaturity