Doorknob (noun)

1. A round or cylindrical handle, typically made of metal or glass, attached to a door and used to open or close it.
2. A knob attached to the outside of a door, used to open it.

Origin:

The word doorknob is a compound of two words door and knob, first recorded usage in the 17th century.

Examples:

1. She twisted the doorknob and opened the door.
2. He replaced the old doorknob with a new one.
3. The doorknob was cold to the touch.
4. He couldn't turn the doorknob because it was locked.
5. The doorknob on the front door was brass.