English Reference

Word

arbitrarily

Phoneticsar·bi·trar·i·ly

US/ˈɑɹbɪˌtɹɛɹəɫi/

UK/ˌɑːbɪtɹˈɛɹəli/

Definitions

01without a logical reason

C1

adv. doing something based on a random choice or a personal whim instead of using a fair system or logic.

adv. in a manner based on random choice or personal whim, rather than any reason or system. Often carries a negative connotation of unfairness in administrative or legal contexts.

“The teacher seemed to pick students arbitrarily rather than following the alphabet.”

“The committee was criticized for arbitrarily changing the entry requirements just weeks before the application deadline.”

Academic

Usage

Typically modifies verbs related to decision-making, such as 'chosen', 'selected', 'assigned', or 'determined'.

Teaching tip

Learners often confuse this with 'randomly'; while similar, 'arbitrarily' often implies a human choice that lacks a fair justification.

Synonyms

randomlycapriciouslyhaphazardly

02to any degree or value

C2 · Math

adv. to any size or amount, often used when the exact number does not matter for the result.

adv. to an unspecified or unrestricted degree; in mathematics, used to indicate that a value can be as large or small as desired.

“You can make the window arbitrarily small by dragging the corner.”

“The sequence can be shown to stay within the limit for an arbitrarily large number of iterations.”

Technical · Academic

Usage

Commonly precedes adjectives like 'large', 'small', 'high', or 'low' to indicate a lack of fixed bounds.

Synonyms

indefinitelyunrestrictedly

Antonyms

fixedlyspecifically

Real-World Examples

“However, what most share is the need to unburden a guilty conscience and a desire to assign cause and meaning to the bad things that life seems to arbitrarily dole out.”
Aeon · 19 Aug 2026
“There’s something almost audacious in the randomness of the play’s narrative development, as if they’d set themselves the challenge of accepting every first idea, however arbitrarily it advances the plot.”
The Guardian · 14 Aug 2026

Etymology

From arbitrary + -ly.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

arbitrarilyAdverbarbitraryAdjective

This entry

Level
C1 · Advanced
Frequency
Frequent
Updated

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English Reference