infantilism

名词 infantilism:

1. an abnormal condition in which an older child or adult retains infantile characteristics
2. infantile behavior in mature persons

in.fan.til.ism

n.（名词）
A state of arrested development in an adult, characterized by retention of infantile mentality, accompanied by stunted growth and sexual immaturity, and often by dwarfism.
幼稚病：一种出现于成年人当中的发育停滞的状态，其特点是思维幼稚，伴有发育不良和性方面的不成熟，还有侏儒现象发生

Extreme immaturity, as in behavior or character:
幼稚型：如在行为或性格上表现的特别不成熟：
例句：
.infantilism, which is the subtext of so much American cinema and culture.(John Simon)
.幼稚病是许多美国电影和文化的特征.(约翰·西蒙)

An infantile act or remark.
幼稚行为：幼稚的行为或言论