adj.嬰兒的；幼稚的；孩子氣的

Some infantile actions survive into adulthood. 某些嬰兒期的行為一直保持到成年期。

And I will hear no more of your infantile excuses. 還有，我不要再聽到你那些幼稚的借口。

His behaviour is infantile for a man of 35. 他的這種行為對于三十五歲的人來說是太幼稚了。

The immature parents have so many infantile traits themselves. 這對未成熟的父母本身就有不少孩子氣。