1. devices attached to doors that are used for knocking to announce one’s presence
Usage: plural of knocker
2. people who knock on doors or surfaces
Usage: plural of knocker
3. people who criticize or find fault with something
Usage: informal; plural of knocker

Examples

• The old house had brass knockers on both the front and back doors.
• Victorian knockers were often ornately decorated with lion heads or other designs.
• The census takers were persistent knockers, returning several times to each address.
• Don’t listen to the knockers who say it can’t be done.
• Every successful project has its knockers and supporters.
• The antique shop specialized in restored door knockers from the 18th century.