乳ちち臭くさい

i-adjective

green; wet behind the ears; immature

Idiomatic expression describing someone as inexperienced, naive, or childish, often with a critical tone. The literal meaning 'smelling of milk' is rarely used outside of explaining the idiom.

• 彼かれはまだ乳ちち臭くさいから、大だい事じな仕し事ごとは任まかせられない。

  He's still green, so I can't entrust him with important work.

• そんな考かんがえ方かたは乳ちち臭くさいよ。

  That way of thinking is immature.