moderator

noun

mod·​er·​a·​tor ˈmä-də-ˌrā-tər 

plural moderators

1

: someone who presides over an assembly, meeting, or discussion: such as

a

: the chairperson of a discussion group

b

: a person who administers an online forum, chat room, or group

c

: the nonpartisan presiding officer of a town meeting

d

: the presiding officer of a Presbyterian governing body

2

: one who arbitrates : mediator

3

: a substance (such as graphite) used for slowing neutrons in a nuclear reactor

moderatorship

ˈmä-də-ˌrā-tər-ˌship 

noun

Synonyms of moderator

• chairperson
• president
• chairman
• presider

Examples of moderator in a Sentence

The moderator allowed audience members to ask the governor questions.

She acts as the moderator in our office meetings.

Recent Examples on the Web

Every Sunday, moderator and CBS News chief foreign affairs correspondent Margaret Brennan (@margbrennan) interviews principal newsmaker guests on topics driven by the news of the week. —CBS News, 4 June 2026

Among those set to join the Hot Topics table in the episodes ahead are longtime fill-in panelist Sheryl Underwood, journalist Kara Swisher, and extending moderator Whoopi Goldberg's panel time into Fridays for the time being, though the EGOT winner typically has the day off each week. —Joey Nolfi, Entertainment Weekly, 1 June 2026

Later that day, moderators of a Democratic primary debate asked Stevens what AIPAC’s support for her meant. —David Weigel, semafor.com, 1 June 2026

Since taking the reins of the program as moderator in 2023, Welker has worked to broaden the conversation. —Brian Steinberg, Variety, 31 May 2026

Word History

First Known Use

circa 1560, in the meaning defined at sense 2

Rhymes for moderator

• activator
• actuator
• agitator
• alligator
• allocator
• alternator
• animator
• annotator
• applicator
• arbitrator
• aspirator
• aviator

Kids Definition

moderator

noun

mod·​er·​a·​tor ˈmäd-ə-ˌrāt-ər 

1

: one that moderates: as

a

: the leader of a Presbyterian governing body

b

: the chairperson of a town meeting

c

: the chairperson of a discussion group (as on television)

2

: a substance (as graphite) used for slowing down neutrons in a nuclear reactor

Medical Definition

moderator

noun

mod·​er·​a·​tor ˈmäd-ə-ˌrāt-ər 

: a substance (as graphite, deuterium in heavy water, or beryllium) used for slowing down neutrons in a nuclear reactor