arbitrary

Meanings

1. 1adjectivecomparable

   Decided or done on a whim or by chance, without any clear reason, plan, or fair standard behind the choice.

   Grammar: Can come before a noun (an arbitrary rule) or after a verb (the rule seems arbitrary).

   Patterns

   • an arbitrary decision
   • seem arbitrary to someone

   The teacher's grading felt arbitrary because two similar essays got very different marks.

   They picked an arbitrary date for the meeting just to have something on the calendar.

   It seems arbitrary to ban one kind of sandwich but allow another.

2. 2adjectivebefore a nounformal

   Using power freely and without limits, in a way that ignores rules or the rights of others.

   Grammar: Usually appears before words like arrest, power, or rule: arbitrary arrest.

   Patterns

   • arbitrary power
   • arbitrary arrest

   The report condemned the arbitrary detention of journalists.

   A king with arbitrary power can change the laws whenever he likes.

   Citizens were afraid of arbitrary punishment by local officials.

3. 3adjectivebefore a nounmathematicstechnical

   In mathematics and science, left open so that any value or choice may be used, not fixed to one particular case.

   Grammar: Used before nouns such as constant, number, or point: let x be an arbitrary number.

   Patterns

   • an arbitrary constant
   • an arbitrary point

   Take an arbitrary triangle and measure its angles.

   The proof works for any arbitrary integer.

   Choose an arbitrary point on the line to begin.

Common combinations

arbitrary decision

Firing him without warning was an arbitrary decision.

arbitrary rule

Students complained about the arbitrary rule on hair length.

arbitrary choice

Any name is fine; it is an arbitrary choice.

arbitrary detention

Human rights groups protested against arbitrary detention.

purely arbitrary

The cutoff score seemed purely arbitrary.

Synonyms and how they differ

random

Random stresses lack of pattern or aim, while arbitrary adds the idea that someone chose without a good reason.

capricious

Capricious suggests sudden, unpredictable changes of mood or mind, and is more formal and critical than arbitrary.

unreasoned

Unreasoned says no thought was given, whereas arbitrary often implies power used unfairly.

whimsical

Whimsical is playful or fanciful, often with a gentle tone, unlike the usually critical arbitrary.

Opposites

Word family

arbitrarily adverb

in a way that is not based on a reason or system

arbitrariness noun

the quality of being arbitrary

arbitrate verb

to settle a dispute as a neutral judge

arbitration noun

the settling of a dispute by an outside judge

Commonly confused: arbitrary or arbitrate?

Practice

Make it your own

Write a sentence using “arbitrary”, then check it and compare it with the examples above.

Explore more words