1. Someone who refuses to accept, especially as to reject as unauthorized or as having no binding force: At the meeting and after the chairman had scrutinized the contract, he presented himself as the repudiator and rejected it as being a fake!
2. Anyone who rejects as untrue or unjust: The repudiator turned out to be a young woman who denied having stolen the dress at the shop because she wasn't there at the time when it happened.