Synonyms of mediator
1
: one that mediates
especially : one that mediates between disputing parties
2
: a mediating agent in a physical, chemical, or biological process

Examples of mediator in a Sentence

if you two cannot resolve this argument on your own, we'll have to bring in a mediator
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
All three have the advantage of leveraging their strong ties with both Iran and the US to serve as more effective mediators. — Lauren Morganbesser, semafor.com, 22 Sep. 2026 Egypt has been a key mediator and borders the Palestinian territory. — Arkansas Online, 21 Sep. 2026 Preclinical research also suggests that quinoa saponins may reduce the production of inflammatory mediators and pro-inflammatory molecules. — Amy Brownstein, Verywell Health, 4 Sep. 2026 Qatar has been an important mediator in the US-Iran conflict. — Brad Lendon, CNN Money, 27 Aug. 2026 See All Example Sentences for mediator

Word History

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of mediator was in the 14th century

Browse Nearby Words

Cite this Entry

“Mediator.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mediator. Accessed 26 Sep. 2026.

Kids Definition

mediator

noun
: one that mediates
mediatory
-ē-ə-ˌtōr-ē, 
-ˌtȯr-
adjective

Medical Definition

mediator

noun
: one that mediates
especially : a mediating agent (as an enzyme or hormone) in a chemical or biological process
substance P, a neuropeptide mediator of analgesic stimuli in peripheral sensory nerves —D. R. Robinson

Legal Definition

mediator

noun
: one that works to effect reconciliation, settlement, or compromise between parties at variance compare arbitrator
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