adjective

arbitrary

/ˈɑːrbɪtreri/ · say it: AHR·bi·trer·ee

based on random choice rather than reason

In Sophisticated Everyday

In more detail

1. (adjective) based on personal choice or opinion rather than on reason or logic

2. (adjective) decided or chosen without any fair or logical reason; seeming random or unfair

Examples

1. The rules seem arbitrary because there's no clear explanation for why they exist.
2. The judge made an arbitrary decision to increase the punishment without explaining why.

How to use arbitrary

Arbitrary describes choices or actions that lack a rational basis or fair justification, often implying unfairness or randomness. It differs from 'capricious' (which emphasizes sudden, whimsical changes) and 'subjective' (which emphasizes personal perspective rather than objective standards). Used in academic, professional, and everyday contexts to criticize decisions perceived as unjust or unreasoned.

Common phrases

arbitrary decision
arbitrary choice
arbitrary rule
seemingly arbitrary
arbitrary power

Synonyms

capricious · whimsical · random · discretionary · subjective

Opposites

rational · logical · justified

Word family

arbitrarily (adverb) · arbitrariness (noun) · arbitrate (verb - different root) · arbitrator (noun - different root)

A common mistake

Learners sometimes confuse 'arbitrary' with 'arbiter' or 'arbitrate,' which come from a different Latin root and mean to judge or mediate disputes.

Learn it for good

Save this word in WordVale and it comes back for review right before you'd forget it — with pronunciation, real examples, and optional translations. One purchase, no subscription.

Get WordValeFREE 7-DAY TRIAL · iPHONE & iPAD