What is Moderator?

Moderator definition and meaning on Dictionary terms:
a person or thing that moderates.
a person who presides over a panel discussion on radio or television.
a member of an online message board or electronic mailing list with privileges and responsibilities to approve or reject messages and uphold the terms of service.
a presiding officer, as at a public forum, a legislative body, or an ecclesiastical body in the Presbyterian Church.
Physics. a substance, as graphite or heavy water, used to slow neutrons to speeds at which they are more efficient in causing fission.

RELATED WORDSreferee, mediator, peacemaker, alleviator, stabilizer, pacifier, soother