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

Mashaal said the group has offered multiple options, including a long-term truce, as part of ongoing negotiations with Egyptian, Qatari and Turkish mediators. —Samy Magdy, Los Angeles Times, 8 Feb. 2026

By replacing the mediator with mutant plants, the receiver plants failed to get protection against the stress. —New Atlas, 7 Feb. 2026

Before the 12-day Iran-Israel war in June, Tehran and Washington had gone through five rounds of negotiations, where Omani mediators shuttled between US and Iranian delegations. —Nadeen Ebrahim, CNN Money, 6 Feb. 2026

Minnesota Attorney General Keith Ellison’s office, which regulates charities, became involved in discussions and assisted with finding mediators. —Frederick Melo, Twin Cities, 30 Jan. 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