1. a person who has strange or crazy ideas
Usage: informal

1. having strange or unrealistic ideas; eccentric
Usage: informal

Examples

• The professor dismissed him as a crackpot with wild theories.
• She’s known for her crackpot ideas about alien visitors.
• His crackpot scheme to get rich quick failed miserably.
• The newspaper refused to publish the crackpot’s letter.
• Don’t listen to those crackpot conspiracy theories.
• The inventor was labeled a crackpot until his device actually worked.