moderator
[ mod-uh-rey-ter ]
/ ˈmɒd əˌreɪ tər /
noun
a person or thing that moderates.
a person who presides over a panel discussion on radio or television.
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.
a presiding officer, as at a public forum, a legislative body, or an ecclesiastical body in the Presbyterian Church.
Physics. a substance, as graphite or heavy water, used to slow neutrons to speeds at which they are more efficient in causing fission.
RELATED WORDS
Nearby words
- moderately,
- moderation,
- moderationist,
- moderations,
- moderato,
- modern,
- modern apprenticeship,
- modern art,
- modern cut,
- modern dance
Origin of moderator
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for moderator
moderator
/ (ˈmɒdəˌreɪtə) /
noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
moderator
late 14c., "ruler, governor," from Latin moderator "manager, ruler, director," literally "he who moderates," from moderatus (see moderate (adj.)). Meaning "one who acts as an umpire" is from 1560s. Fem. form moderatrix attested from 1530s.
Online Etymology Dictionary, © 2010 Douglas Harper
moderator
[ mŏd′ə-rā′tər ]
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). Also called neutron moderator See also slow neutron.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.