keep one's nose clean

keep (one's) nose clean

To stay out of trouble. You better keep your nose clean, kid, or you're going to run into trouble you can't handle.
See also: clean, keep, nose

keep one's nose clean

Stay out of trouble. For example, Dad told Brian to keep his nose clean from now on or he'd cut off his allowance. [Colloquial; late 1800s]
See also: clean, keep, nose