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

After sitting out on Monday, as Behar typically has that day off on the weekly schedule, Ana Navarro filled in for the cohost on Tuesday's broadcast, with moderator Whoopi Goldberg informing the audience why Behar wasn't on the show that day. —Joey Nolfi, Entertainment Weekly, 28 Jan. 2026

On another matter, responding to a question from one of the debate’s moderators, none of the three Senate candidates offered support for Chicago Mayor Brandon Johnson’s reelection in 2027. —Rick Pearson, Chicago Tribune, 27 Jan. 2026

The candidates will answer questions from moderators Daniel Marin, news anchor of Austin TV station KXAN, and Gromer Jeffers, political reporter for the Dallas Morning News. —Marley Malenfant, Austin American Statesman, 24 Jan. 2026

And of course, last but not least is our moderator. —Outside Online, 21 Jan. 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