dry behind the ears

So they got kind of upset, this female making more money than I am, and she just out of college, not even dry behind the ears.

“You boys ain’t dry behind the ears yet when it comes to shootin’ scrapes.”

Young, no more than twenty-five, but very dry behind the ears.

You might have an LLM, but are you dry behind the ears yet?”

Sir: With all the noise about Senator John F. Kennedy's being Roman Catholic, no one has mentioned that he is only 42 years old and hardly "dry behind the ears."