arbiter

noun

ar·​bi·​ter ˈär-bə-tər 

1

: a person with power to decide a dispute : judge

The mayor will act as the final arbiter in any dispute between board members.

2

: a person or agency whose judgment or opinion is considered authoritative

arbiters of taste

Did you know?

Are arbiter and arbitration arbitrary?

A large portion of the words we use today come from Latin roots. Many of these words retain a meaning that is closely related to their Latin ancestor, although sometimes they will drift a considerable distance from their roots (sinister, for instance, had the meaning of “on the left side” in Latin, but also meant “unlucky, inauspicious”). In some instances, a single Latin word will give rise to multiple words in English, some of which have strayed in meaning, and others which have not.

An example of this may be found in our word arbiter. We trace it to the Latin root with the same spelling, arbiter, meaning “eyewitness, onlooker, person appointed to settle a dispute.” A number of English words stem from the Latin arbiter, many of which have to do with judging or being a judge. An arbiter is a judge, and arbitration is the act of judging, or serving as an arbiter. Yet the most common meaning of arbitrary is “existing or coming about seemingly at random or by chance or as a capricious and unreasonable act of will,” which seems to be quite a bit different in meaning from the other two words. Arbitrary does indeed come from the same Latin root, and its oldest meaning in English was “depending on choice or discretion particularly regarding the decision of a judge or a tribunal.” But over time it developed additional senses that are somewhat removed from that initial meaning.

Synonyms

• referee
• judge
• umpire
• arbitrator

Examples of arbiter in a Sentence

Recent Examples on the Web

The uncomfortable truth is that economics, not ethics, will be the final arbiter of the transition's speed, even if ethics gets to set the goal. —Alexander Puutio, Forbes.com, 28 June 2025

Republicans suffered a series of setbacks after several proposals were determined to be out of compliance by the chief arbiter of the Senate’s rules. —Alicia Adamczyk, Fortune, 28 June 2025

Senators are still awaiting rulings from the parliamentarian, the nonpartisan arbiter of Senate rules, on some of the most controversial elements of the tax bill, while fiscal hawks are attempting to tap the brakes with a request for more time. —David Sivak, The Washington Examiner, 27 June 2025

The answer could define the region for decades to come, and be the ultimate arbiter of US President Donald Trump’s decision to embark on another conflict in the Middle East. —Nick Paton Walsh, CNN Money, 22 June 2025

Word History

Etymology

Middle English arbitour, arbitre, borrowed from Anglo-French, borrowed from Latin arbiter "eyewitness, onlooker, person appointed to settle a dispute," perhaps, if going back to *ad-biteros, from ad- ad- + *-biteros, derivative from a base *-bit- akin to bītere, baetere, bētere "to go," of obscure origin

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing arbiter

• arbiter elegantiarum

Kids Definition

arbiter

noun

ar·​bi·​ter ˈär-bət-ər 

1

: arbitrator

2

: a person whose judgment or opinion decides what is right or proper

an arbiter of taste

Legal Definition

arbiter

noun

ar·​bi·​ter ˈär-bə-tər 

: arbitrator

Etymology

Latin, onlooker, arbitrator