an abnormal condition in which an older child or adult retains infantile characteristics
infantile behavior in mature persons
例句
It was heresy of crackpots and wild men and it was really just an infantilism. 那是狂想家和过激分子的异端邪说的产物，实在不过是幼稚病而已。
And after 7-year development, the security investment funds have gradually grown into maturation from infantilism. 经过七年的努力，证券投资基金经历了从无到有，从单一到多样，从幼稚到成熟的发展过程。
A 19-year-old girl of 45,X/46,XY mosaic Turner syndrome, presenting with short stature, sexture, sexual infantilism and abnormal physical stigmata was found to have a left adnexa mass at diagnosis. 摘要透纳氏症患者中约有百分之二十为镶嵌型染色体异常，其中少部份带有Y染色体。
