Schmuck (noun)

1. A stupid, foolish, or contemptible person.
2. An obnoxious or contemptible person.

Origin:

Yiddish shmok, from middle high german smoc "penis".

Examples:

1. He's such a schmuck, always thinking about himself.
2. The schmuck cut in front of me in line.
3. The schmuck's behavior was unacceptable.
4. He was called a schmuck for his rude behavior.
5. The schmuck ruined the party for everyone.