mod·​er·​a·​tor | \ˈmä-də-ˌrā-tər \

Definition of moderator 

1 : one who arbitrates : mediator

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

a : the presiding officer of a Presbyterian governing body

b : the nonpartisan presiding officer of a town meeting

c : the chairman of a discussion group

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

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Other Words from moderator

moderatorship \ -​ˌship \ noun

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

The reading, though a launch for Cantú’s book, was (perhaps wisely, in hindsight) set up as a panel with another writer and a moderator. Marie Myung-ok Lee, Longreads, "Politics and Prose," 18 May 2018 Yelp’s moderators are also up against people like conservative activist Charlie Kirk, who encouraged his more than 600,000 Twitter followers Sunday to leave 100,000 additional reviews on the Red Hen’s page. Louise Matsakis, WIRED, "The Red Hen and the Weaponization of Yelp," 26 June 2018 Their appeal will be sent to a new human moderator, who will issue a decision within 24 hours. Alyssa Newcomb /, NBC News, "Facebook reinstates Declaration of Independence post after mistakenly flagging it as hate speech," 5 July 2018 The format is simple: a moderator, customarily female, lobs a question to the two stars of the show (always male, so far, save for days when somebody is sick or on vacation). Vinson Cunningham, The New Yorker, "Stephen A. Smith Won’t Stop Talking," 16 June 2018 But instead of having Facebook’s moderators, human or otherwise, make editorial decisions, there’s been a subtle shift to let news organizations do so. Barbara Ortutay, USA TODAY, "Facebook to cut 'trending' news section, source of conservative backlash," 1 June 2018 Rapid change also has caused high turnover among Facebook content moderators in some cities, people familiar with the matter say. Deepa Seetharaman, WSJ, "Facebook Throws More Money at Wiping Out Hate Speech and Bad Actors," 15 May 2018 The moderator, Reuters journalist Anna Irrera, called for a time out to cool things off. Bloomberg, Fortune, "A Verbal Cryptobrawl Broke Out at the Milken Institute Global Conference," 2 May 2018 Google so far has been relying on those moderators and other employees to flag instances of abuse on their forums, which triggers a review by human resources staff. Douglas Macmillan, WSJ, "Google Reins In Workplace Debate," 28 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'moderator.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of moderator

circa 1560, in the meaning defined at sense 1

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Statistics for moderator

Last Updated

11 Nov 2018

Look-up Popularity

Time Traveler for moderator

The first known use of moderator was circa 1560

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More Definitions for moderator



English Language Learners Definition of moderator

: someone who leads a discussion in a group and tells each person when to speak : someone who moderates a meeting or discussion


mod·​er·​a·​tor | \ˈmäd-ə-ˌrāt-ər \

Medical Definition of moderator 

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

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Comments on moderator

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a private place of worship

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