Визначення та Значення "[keep] {one's} nose clean"

What is the origin of the idiom "keep one's nose clean" and when to use it?

The idiom "keep one's nose clean" is thought to have originated in the United States in the early 20th century. The phrase likely derives from the idea that a person who stays out of trouble or avoids wrongdoing tends to have a clean, unblemished reputation. This phrase is used to refer to an individual who avoids engaging in unlawful or morally questionable activities and behaves in a manner that avoids suspicion or wrongdoing.