mediator

noun

me·​di·​a·​tor ˈmē-dē-ˌā-tər 

1

: one that mediates

especially : one that mediates between parties at variance

2

: a mediating agent in a physical, chemical, or biological process

Synonyms

• negotiator
• conciliator
• intermediary
• peacemaker
• broker
• ambassador
• intercessor
• liaison
• middleman
• buffer
• attorney

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

Negotiations to secure a 60-day ceasefire between Israel and Hamas seem to have hit an impasse amid hopes from top mediators, including President Donald Trump’s Middle East Special Envoy Steve Witkoff, that a deal can be reached soon. —Caitlin McFall, FOXNews.com, 13 July 2025

And that then triggers these cells, called the mast cells, to release all these inflammatory mediators, like histamine and other kinds of mediators, like nutrients, which can have profound effects. —Josh Hammer, MSNBC Newsweek, 9 July 2025

Tehran, for its part, was once again open to speaking directly to American officials rather than exclusively through mediators. —Mohammad Ayatollahi Tabaar, Foreign Affairs, 8 July 2025

Another way that cortisol can help manage stress in the short term is by suppressing your immune system and the release of different inflammatory mediators. —Bruce Y. Lee, Forbes.com, 5 July 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for mediator

• activator
• actuator
• agitator
• alligator
• allocator
• alternator
• animator
• annotator
• applicator
• arbitrator
• aspirator
• aviator

Kids Definition

mediator

noun

me·​di·​a·​tor ˈmēd-ē-ˌāt-ər 

: one that mediates

mediatory

-ē-ə-ˌtōr-ē

-ˌtȯr-

adjective

Medical Definition

mediator

noun

me·​di·​a·​tor ˈmēd-ē-ˌāt-ər 

: 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

me·​di·​a·​tor ˈmē-dē-ˌā-tər 

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