moderator

American  

[mod-uh-ray-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

“No,” Raman then said firmly before shrugging and letting the moderator move on to the next question.

From Los Angeles Times ● Aug. 20, 2026

“Just disgusting behavior by an anonymous account,” Chuck Todd, a former Meet the Press moderator, wrote of the post that mentioned Holmes’ children.

From Slate ● Aug. 18, 2026

“We are discussing the best way to discourage these larger brands to infiltrate possibly the very last place on the internet for genuine company reviews and feedback,” the moderator added.

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

Martha Ackmann served as moderator and, along with the eight women who could attend, told the story.

From "Women in Space" by Karen Bush Gibson

A halfway house is a New York Times podcast whose moderators ape the shouty persona of comedian John Mulaney.

From The Wall Street Journal ● Sep. 8, 2026

But moderators who were historically more lenient toward promotional posts have started pushing back after a deluge of Reddit posts designed to manipulate AI search results.

From The Wall Street Journal ● Aug. 14, 2026

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

From Los Angeles Times ● Aug. 12, 2026

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

From Salon ● Aug. 6, 2026

For while we smoked we were both moderators, and even an Assembly clerk could not have told which was which.

From St. Cuthbert's by Robert E. Knowles

Related Words

• mediator
• referee