rumormonger
/ˈruːmərˌmʌŋɡər/
noun
- A person who spreads rumors, especially ones that are unkind or harmful.
- The office rumormonger started a false story about the manager quitting.
- The town's biggest rumormonger was always causing trouble with her gossip.
- Don't be a rumormonger; if you don't know it's true, don't repeat it.