IPA: /ˈɑːrbɪtər/
KK: /ˈɑːr.bɪ.tər/
A person who is chosen to make a decision or judgment in a disagreement or dispute.
The arbiter settled the argument between the two parties fairly.
Arbiter is derived from the Latin word "arbitrare" (meaning to judge or to consider) and the suffix "-er" (meaning one who). The word "arbiter" refers to one who judges or decides in a dispute.
Think of someone who 'judges' ('arbitrare') a situation — that's why an arbiter is a person who makes decisions.