Doorbell (noun)

A bell or other device that makes a noise when someone pushes a button or pulls a cord in order to let someone know that they are at the door.

Origin:

Late 19th century: from door + bell.

Examples:

1. He rang the doorbell and waited for someone to answer.
2. The doorbell has a camera so you can see who's there.
3. Please ring the doorbell when you arrive.
4. The doorbell was ringing constantly.
5. The doorbell had a distinctive chime.