Main Entry: mod·er·a·tor

Pronunciation: \ˈmä-də-ˌrā-tər\

Function: noun

Date: circa 1560

1 : one who arbitrates : mediator
2 : one who presides over an assembly, meeting, or discussion: as a : the presiding officer of a Presbyterian governing body b : the nonpartisan presiding officer of a town meeting c : the chairman of a discussion group
3 : a substance (as graphite) used for slowing neutrons in a nuclear reactor

— mod·er·a·tor·ship \-ˌship\ noun