mediator

noun

me·​di·​a·​tor ˈmē-dē-ˌā-tər 

1

: one that mediates

especially : one that mediates between disputing parties

2

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

Synonyms of mediator

• 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

Federal and state mediators have been involved. —Paula Wethington, CBS News, 3 Mar. 2026

Gritz attempted to act as a mediator in other standoffs later in the decade but did not find the same success. —Joseph Wilkinson, New York Daily News, 2 Mar. 2026

Oman, acting as mediator, said progress had been made, but heading into the weekend, there were no signs of an immediate breakthrough. —Michael Collins, USA Today, 28 Feb. 2026

Vance meets with mediator Iran and the United States on Thursday walked away from another round of nuclear negotiations in Geneva without a deal. —Sam Metz, Chicago Tribune, 27 Feb. 2026

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