knocker
/ˈnɑkər/
noun
- A metal or wooden object attached to a door that you hit to announce your arrival.
- I heard the knocker and ran to answer the door.
- She lifted the heavy brass knocker and let it fall three times.
- The old house had a lion-shaped knocker on the front door.
- A person who criticizes or finds fault with someone or something.
- He's a constant knocker, always complaining about the team's performance.
- Ignore the knockers; your work is excellent.
- Every new idea has its knockers who say it won't work.