moderator

American  

[mod-uh-rey-ter] / ˈmɒd əˌreɪ tər /

noun

• moderators
  plural

1. a person or thing that moderates.

2. a person who presides over a panel discussion on radio or television.

3. 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.

4. a presiding officer, as at a public forum, a legislative body, or an ecclesiastical body in the Presbyterian Church.

5. Physics. a substance, as graphite or heavy water, used to slow neutrons to speeds at which they are more efficient in causing fission.

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moderator British  

/ ˈmɒdəˌreɪtə /

noun

1. a person or thing that moderates

2. Presbyterian Church a minister appointed to preside over a Church court, synod, or general assembly

3. a presiding officer at a public or legislative assembly

4. a material, such as heavy water or graphite, used for slowing down neutrons in the cores of nuclear reactors so that they have more chance of inducing nuclear fission

5. an examiner at Oxford or Cambridge Universities in first public examinations

6. (in Britain and New Zealand) one who is responsible for consistency of standards in the grading of some educational assessments

7. a person who monitors the conversations in an on-line chatroom for bad language, inappropriate content, etc

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moderator Scientific  

/ mŏd′ə-rā′tər /

1. A substance, such as graphite, water, or heavy water, placed in a nuclear reactor to slow neutrons down to speeds at which they are more likely to be captured by fissionable components of a fuel (such as uranium-235) and less likely to be absorbed by nonfissionable components of a fuel (such as uranium-238).

2. Also called neutron moderator

3. See also slow neutron

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Other Word Forms

Derived Forms

• moderatorship
  noun
• moderatorial
  adjective

Inflected Forms

Nouns

• moderators
  plural

Etymology

Origin of moderator

1350–1400; Middle English < Latin moderātor, equivalent to moderā ( rī ) to control ( see moderate) + -tor -tor

Explanation

Someone who oversees a meeting, debate, or discussion is called a moderator. It's the moderator's job to make sure that none of the candidates go over their allotted time when they answer debate questions. A debate moderator has an important job, asking questions, maintaining order, and cutting off speakers when they're officially run out of time for a response. In a meeting, a moderator has similar tasks, ensuring that everyone gets a chance to speak — but not for too long. Online moderators can delete threatening, vulgar, or spam messages, and they also make sure discussions stay on topic. Moderators can also be more like mediators, negotiating disputes and helping people reach agreements.

Example Sentences

See Examples For:

moderator moderators

“If there’s a sudden wave of positive Brilliant Earth content on here, it might not be coincidental,” a moderator warned the Reddit community devoted to jewelry, accompanying the message with a siren emoji.

From The Wall Street Journal ● Aug. 14, 2026

A moderator error caused a delay in the removal, TikTok said, but the company alerted law enforcement to the situation, closed several subsequent streams within 90 seconds, and banned the account.

From BBC ● Aug. 9, 2026

They flagged Hilton’s alarming livestream within minutes, closed other live streams within 90 seconds and banned the account, the spokesperson said, but its removal was delayed by what was characterized as “a moderator error.”

From Salon ● Aug. 6, 2026

A spokesperson for TikTok told The Times on Wednesday that the social platform’s automated moderation systems flagged the livestream within minutes but that a moderator error caused a delay in the removal.

From Los Angeles Times ● Aug. 5, 2026

In this way, Goddard’s voice began to supplant his own internal moderator.

From "Scythe" by Neal Shusterman

But many of Reddit’s de facto rulers—the unpaid, mostly-anonymous moderators who police each subreddit and wield automated management tools—are determined to keep any other whiff of marketing out of the organic feeds they lovingly cultivate.

From The Wall Street Journal ● Aug. 14, 2026

Reddit Marketing Agency promises on its website to post comments for clients using “profiles that moderators recognize as legitimate community members” and reduce the visibility of negative comments.

From The Wall Street Journal ● Aug. 14, 2026

Frightened fans and moderators from the social platform were among those who called authorities.

From Los Angeles Times ● Aug. 7, 2026

Teams of human moderators once employed by all the major platforms have been gutted.

From Salon ● Aug. 6, 2026

Observe that minutes of proceedings can be no proof, for they were made by no authentic persons; registers were kept by no warranted officers; chairmen and moderators were chosen without authority.

From The Great Speeches and Orations of Daniel Webster With an Essay on Daniel Webster as a Master of English Style by Daniel Webster

Related Words

• mediator
• referee