mature加前缀immature ,immature中文意思是adj. 发育未全的(人)幼稚的,不成熟的粗糙的

e was a young fellow, very green, very immature.他是个年轻的家伙,没什么经验,很不成熟。

We are probably immature and over-trusting.我们可能是不成熟并信任过度。