repudiator
/ˌrɛpyʊˈdɪˌeɪtər, rɛpˌjuːdɪˈeɪtər/Definitions
1. noun
A person who repudiates or refuses to acknowledge something, especially a debt or an obligation.
“The company was sued by several creditors, who accused the repudiator of deliberately withholding payments.”
2. noun
A person who refuses to acknowledge or accept something, especially a fact or an idea.
“The repudiator of the scientific consensus on climate change faced intense criticism from experts in the field.”