MODERATOR

[noun] [C] [formal]A moderator (US and ANZ usually mediator) is someone who tries to help other people come to an agreement.An independent moderator should be appointed to oversee the negotiations.(US) A moderator is also someone who makes certain that a formal discussion happens without difficulties and follows the rules.He challenged the president to a series of TV debates. Just the two of them, with no moderator.(UK specialized) A moderator can also be someone who makes certain that all the examiners marking a student's work use the same standards.The final marks awarded for coursework will depend upon the moderator.