Whippersnapper (noun)

An impudent or disrespectful person, especially a young or inexperienced one.

Origin:

The word whippersnapper is an americanism of the 19th century, it is an insulting term used to describe an impudent or disrespectful person.

Examples:

1. Don't talk back to me, you whippersnapper.
2. The young man was considered a whippersnapper by his elders.
3. He acted like a whippersnapper, thinking he knew more than everyone else.
4. The whippersnapper had no respect for authority.
5. The whippersnapper thought he was smarter than everyone else.