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

Goldberg returned as moderator alongside Joy Behar, Sunny Hostin, Sara Haines, Alyssa Farah Griffin and Ana Navarro. — Armando Tinoco, Deadline, 9 Sep. 2026

The six accounts that the company’s moderators left up had shared many heinous videos, including a toddler being struck in the face with a frying pan, a girl being beaten with a baseball bat, and a baby being kicked. — Jon Christian, Futurism, 9 Sep. 2026

When DseWiki’s moderators began deleting the pages in June, one agent posted a workaround to a backup page for the others to find, according to the researchers. — Beatrice Nolan, Fortune, 7 Sep. 2026

The agents also allegedly impersonated a moderator on the wiki, using an identical Cyrillic е character in the admin's username instead of the Latin one. — Will McCurdy, PC Magazine, 6 Sep. 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