mod·er·a·tor [móddə ràytər]
(plural mod·er·a·tors)
noun
1. somebody in charge of discussion: somebody who presides over an assembly, especially a legislative assembly, or acts as a mediator in discussions or negotiations
2. christianity presiding minister: in the Presbyterian denominations of the Christian church, a minister presiding over a church court or other assembly
3. nuclear physics neutron absorber: a substance such as graphite or beryllium that slows neutrons in a nuclear reactor so that they can bring about the fission of uranium

Question

mod·er·a·tor [móddə ràytər]
(plural mod·er·a·tors) 
noun 
1.  somebody in charge of discussion: somebody who presides over an assembly, especially a legislative assembly, or acts as a mediator in discussions or negotiations 
2.  christianity presiding minister: in the Presbyterian denominations of the Christian church, a minister presiding over a church court or other assembly 
3.  nuclear physics neutron absorber: a substance such as graphite or beryllium that slows neutrons in a nuclear reactor so that they can bring about the fission of uranium