Synonyms of Arbitrarily: 20 Better Alternatives With Examples
Finding the right synonym for arbitrarily is not simply a matter of replacing one word with another. The best alternative depends on why something was done without a clear reason, system, or fair basis. Randomly, haphazardly, capriciously, and indiscriminately overlap with arbitrarily, but each emphasizes something different.
This guide explains the most useful synonyms of arbitrarily, shows how they differ, and gives natural examples so you can choose the right word for academic, professional, and everyday writing.
Quick Answer: What Are the Best Synonyms of Arbitrarily?
Some of the closest synonyms of arbitrarily are randomly, at random, haphazardly, capriciously, indiscriminately, willy-nilly, and without reason. However, they are not interchangeable in every sentence.
Randomly emphasizes chance, haphazardly emphasizes a lack of organization, capriciously emphasizes personal whim, and indiscriminately emphasizes choosing or treating things without distinction.
Core Synonyms of Arbitrarily
| Word or Phrase | Relationship | Main Meaning | Best Context |
|---|---|---|---|
| Randomly | Direct/near synonym | Without a predictable plan or method | Selection, numbers, events |
| At random | Direct synonym | By chance rather than deliberate choice | Selection or assignment |
| Haphazardly | Near synonym | Without order, method, or planning | Arrangements, work, decisions |
| Capriciously | Near synonym | According to sudden personal whims | Decisions, authority, behavior |
| Indiscriminately | Contextual synonym | Without making distinctions | Selection, treatment, distribution |
| Willy-nilly | Contextual alternative | Without careful planning or control | Informal writing |
| Without reason | Contextual alternative | Without a rational explanation | Decisions and actions |
| Aimlessly | Contextual alternative | Without a purpose or goal | Movement, activity, behavior |
| Erratically | Contextual alternative | In an unpredictable or inconsistent way | Behavior, movement, performance |
| Offhandedly | Contextual alternative | Casually, without much thought | Remarks and decisions |
| Casually | Contextual alternative | Without careful consideration | Remarks, choices, treatment |
| At will | Contextual alternative | As one wishes or chooses | Exercise of authority |
| Carelessly | Near synonym | Without sufficient attention or care | Actions and handling |
| Unsystematically | Contextual alternative | Without an organized system | Research, processes, selection |
| Purposelessly | Contextual alternative | Without a clear purpose | Actions or movement |
| Unpredictably | Near synonym | In a way that cannot be reliably predicted | Behavior and outcomes |
| Accidentally | Related, not universal | Unintentionally or by accident | Events and actions |
| By chance | Contextual alternative | Because of chance rather than intention | Discoveries and selections |
| Unreasonably | Contextual alternative | Without reasonable justification | Rules, decisions, demands |
| Wantonly | Strong contextual alternative | Without restraint or justification, often harmfully | Power, destruction, punishment |
The distinctions matter. Major dictionaries connect arbitrarily with acting according to chance, without reason or system, and—in another sense—with exercising power without proper consideration for others.
What Does “Arbitrarily” Mean?
Arbitrarily is an adverb meaning in a way that is not based on a clear reason, system, plan, or consistent principle. It can also describe the unfair or unchecked exercise of personal power.
For example:
The manager arbitrarily changed the schedule.
This suggests that the manager changed it without a clear, consistent, or reasonable basis.
The word can also describe something selected or determined seemingly by chance:
The numbers were arbitrarily assigned to the participants.
Cambridge identifies both the chance/lack-of-reason sense and the unfair exercise of personal power sense. Oxford similarly defines arbitrarily as acting without an apparent reason, system, or plan and, in formal usage, using power without limits while disregarding others.
1. Randomly
Randomly is one of the closest alternatives when arbitrarily means without a predictable selection method or according to chance.
Example:
The software randomly selected ten participants.
Use randomly when chance is the central idea.
Arbitrarily vs randomly
- Arbitrarily can imply that the choice lacks justification.
- Randomly focuses more specifically on chance or unpredictability.
The committee arbitrarily rejected three applications.
This suggests an unjustified decision.
The computer randomly selected three applications.
This suggests a chance-based process.
Best choice: Use randomly when you specifically mean by chance.
2. At Random
At random is a natural phrase meaning without a deliberate selection process or according to chance.
The students were assigned seats at random.
It works particularly well with verbs such as:
- choose
- select
- assign
- pick
- distribute
At random is usually more precise than arbitrarily when a genuine random process is intended.
3. Haphazardly
Haphazardly means without order, organization, method, or careful planning.
The files were haphazardly arranged across the desk.
This differs from arbitrarily because haphazardly emphasizes disorganization.
Compare:
The files were arranged arbitrarily.
The arrangement may have been based on an unexplained choice.
The files were arranged haphazardly.
The arrangement was disorganized or lacking a system.
Best choice: Use haphazardly for messy, unplanned, or poorly organized processes.
4. Capriciously
Capriciously means according to sudden personal preferences, whims, or changing moods.
The director capriciously changed the rules whenever she became dissatisfied.
This is a particularly strong alternative when arbitrarily describes a person’s unpredictable exercise of judgment or authority.
Best choice: Use capriciously when the decision appears driven by whim or personal mood.
Merriam-Webster’s thesaurus places capriciously prominently among words related to arbitrarily.
5. Indiscriminately
Indiscriminately means without distinguishing between people or things that should be treated differently.
The policy was applied indiscriminately to every employee.
It is especially useful when the issue is lack of discrimination or distinction, rather than pure chance.
Compare:
The names were chosen randomly.
This suggests chance.
The names were chosen indiscriminately.
This suggests that relevant differences between the names or people were ignored.
Best choice: Use indiscriminately when something is done without distinction or selection criteria.
6. Willy-Nilly
Willy-nilly is an informal expression meaning without planning, control, or careful consideration.
The documents were distributed willy-nilly.
It can suggest disorder or uncontrolled action and is generally less formal than arbitrarily.
Best choice: Use it in conversational or informal writing, not usually in formal academic or legal prose.
7. Without Reason
Without reason is a clear phrase-level alternative when you want to emphasize the absence of a rational explanation.
The rule was changed without reason.
This is often useful in plain English because it makes the meaning immediately clear.
However, it does not necessarily convey the same sense of personal authority or whim that arbitrarily can convey.
8. Aimlessly
Aimlessly means without a clear purpose, objective, or direction.
He wandered aimlessly around the building.
It can overlap with arbitrarily in certain contexts, but it is not a general replacement.
You would not normally replace:
The judge arbitrarily imposed the penalty.
with:
The judge aimlessly imposed the penalty.
The second sentence does not make sense in the intended context.
Best choice: Use aimlessly for actions that lack purpose or direction.
9. Erratically
Erratically means in an unpredictable, irregular, or inconsistent manner.
The machine has been operating erratically.
It can overlap with arbitrarily when someone’s behavior or decisions are unpredictable.
The manager acted erratically throughout the negotiations.
But erratically does not necessarily imply that the action was unjustified or unfair.
10. Offhandedly
Offhandedly means casually or without much thought or consideration.
He offhandedly dismissed the proposal.
This works when arbitrarily refers to a decision or remark made with little apparent thought.
It is especially useful for:
- comments
- remarks
- dismissals
- casual judgments
11. Casually
Casually can sometimes replace arbitrarily when the intended meaning is without careful consideration.
The issue was casually dismissed.
However, casually is much broader and usually less critical. It does not automatically suggest unfairness or irrationality.
12. At Will
At will means as someone wishes or chooses.
The administrator could alter the settings at will.
This can overlap with the power-related meaning of arbitrarily, but it is not an exact synonym.
At will emphasizes freedom to act, while arbitrarily can carry a negative judgment that the action lacks a proper basis.
Which Synonym Should You Use?
The easiest way to choose is to identify what you want to emphasize.
Choose “randomly” when:
The action is based on chance.
The winners were randomly selected.
Choose “haphazardly” when:
The action lacks organization or method.
The equipment was haphazardly stored.
Choose “capriciously” when:
The action is driven by personal whims.
The policy was changed capriciously.
Choose “indiscriminately” when:
No meaningful distinctions are being made.
The rule was applied indiscriminately.
Choose “erratically” when:
Behavior or performance is unpredictable or inconsistent.
The system behaved erratically.
Choose “offhandedly” when:
Something was done or said casually and without much thought.
She offhandedly rejected the suggestion.
Choose “without reason” when:
You want a simple, direct expression emphasizing the lack of justification.
The fee was increased without reason.
Choose “at will” when:
The emphasis is on someone’s unrestricted ability to act.
The owner could change the terms at will.
Arbitrarily vs. Randomly vs. Haphazardly
These three words are frequently confused.
| Word | Main emphasis | Example |
|---|---|---|
| Arbitrarily | Lack of reason, principle, or fair basis | The rule was changed arbitrarily. |
| Randomly | Chance | The computer randomly selected a number. |
| Haphazardly | Lack of organization or method | The papers were haphazardly arranged. |
A useful rule is:
Chance → randomly
Disorganization → haphazardly
Unjustified choice → arbitrarily
There can be overlap, but the emphasis changes.
Arbitrarily vs. Capriciously
These words are especially close when describing human decisions.
Arbitrarily suggests that something was decided without a reasonable, consistent, or established basis.
Capriciously suggests that someone acted according to a personal whim or unpredictable preference.
The official arbitrarily denied the request.
The decision appears to lack a proper basis.
The official capriciously denied the request.
The decision appears driven by personal whim.
Use capriciously when you want the idea of personal whim to be especially clear.
Arbitrarily vs. Indiscriminately
These words overlap when someone makes choices without appropriate distinctions.
Arbitrarily focuses on the lack of a sound or consistent basis.
Indiscriminately focuses on treating different people or things alike without considering relevant differences.
The applicants were arbitrarily rejected.
The rejection appears unjustified or based on an unexplained choice.
The applicants were rejected indiscriminately.
The rejection was applied without distinguishing between applicants.
Arbitrarily vs. Accidentally
These words should not normally be treated as interchangeable.
Accidentally means unintentionally or by accident.
Arbitrarily means without a clear reason, system, or proper basis.
She accidentally deleted the file.
She did not intend to delete it.
She arbitrarily deleted the file.
She chose to delete it, but apparently without a reasonable or consistent basis.
This is an important distinction because many broad thesaurus lists contain accidentally among related alternatives, but that does not make it a universal replacement for arbitrarily. Collins, for example, groups the words under particular senses rather than treating every listed word as interchangeable in every sentence.
Common Mistakes With “Arbitrarily” Synonyms
Mistake 1: Using “randomly” for every instance
Not every arbitrary action is random.
The manager arbitrarily fired the employee.
This concerns an apparently unjustified exercise of authority, not necessarily chance.
Mistake 2: Using “accidentally” as a direct substitute
An arbitrary decision is generally intentional but unjustified. An accidental action is unintentional.
Mistake 3: Using “aimlessly” for decisions
Aimlessly means without purpose or direction. It does not automatically mean without reasonable justification.
Mistake 4: Treating “at will” as identical
At will emphasizes freedom or unrestricted choice. Arbitrarily can imply criticism of how that freedom is exercised.
Mistake 5: Using informal alternatives in formal writing
Words such as willy-nilly may sound too conversational for academic, legal, or professional writing.
Natural Examples of “Arbitrarily”
Here are examples showing the word in several contexts:
- The committee should not arbitrarily reject qualified applicants.
- The numbers were arbitrarily assigned to each participant.
- The company cannot arbitrarily change the terms of the agreement.
- The boundary was drawn arbitrarily rather than according to a consistent rule.
- The teacher did not arbitrarily choose the reading materials.
- The officials were accused of enforcing the regulations arbitrarily.
Notice how the meaning changes slightly depending on context. In one sentence, arbitrarily can mean without a rational selection basis; in another, it can suggest unfair or unchecked authority.
Related Words That Are Not Always True Synonyms
Some words are semantically related to arbitrarily but should not automatically replace it:
- accidentally — unintentionally
- unpredictably — not reliably predictable
- carelessly — without sufficient care
- casually — without seriousness or formality
- aimlessly — without purpose
- fortuitously — fortunately or by chance
- unwittingly — without realizing something
- informally — in a non-formal manner
These words may work in particular sentences, but each adds a different meaning.
That distinction is important if you want precise vocabulary rather than simply a longer synonym list.
Antonyms of Arbitrarily
Depending on the intended sense, useful opposites include:
- deliberately
- systematically
- methodically
- reasonably
- rationally
- fairly
- consistently
- purposefully
- carefully
- according to established rules
For example:
The applicants were selected arbitrarily.
can be contrasted with:
The applicants were selected systematically according to published criteria.
FAQ: Synonyms of Arbitrarily
What is the closest synonym for “arbitrarily”?
The closest synonym depends on context. Randomly is often appropriate when arbitrarily means according to chance, while capriciously is closer when it means according to personal whim. Haphazardly works when the emphasis is on a lack of order or method.
What is another word for “arbitrarily”?
Common alternatives include randomly, at random, haphazardly, capriciously, indiscriminately, and willy-nilly. The most accurate choice depends on whether you mean chance, disorder, personal whim, or lack of fair distinction.
Is “randomly” the same as “arbitrarily”?
Not always. Randomly specifically emphasizes chance or unpredictability. Arbitrarily can mean acting without a reasonable basis, established system, or principle and can also imply an unfair use of personal power.
What is a formal synonym for “arbitrarily”?
Depending on context, capriciously, indiscriminately, without justification, or without a rational basis may be suitable formal alternatives. The best choice depends on the exact meaning you want to express.
What is the difference between “arbitrarily” and “haphazardly”?
Arbitrarily emphasizes an unexplained, unprincipled, or sometimes unfair choice. Haphazardly emphasizes a lack of order, method, or organization.
What is the difference between “arbitrarily” and “indiscriminately”?
Arbitrarily focuses on the absence of a sound or consistent basis for an action. Indiscriminately focuses on failing to distinguish between people or things that may warrant different treatment.
Can “accidentally” replace “arbitrarily”?
Usually not. Accidentally means unintentionally or by accident, whereas arbitrarily generally describes an intentional action that lacks a clear reason, system, or proper basis.
Is “willy-nilly” a synonym for “arbitrarily”?
It can be a contextual alternative, especially when something is done without planning, control, or careful consideration. However, willy-nilly is informal, so it is not the best choice for every professional or academic context.
Conclusion
The best synonym for arbitrarily depends on the exact meaning you want to preserve. Choose randomly when chance is important, haphazardly when there is a lack of organization, capriciously when personal whim is involved, and indiscriminately when distinctions are ignored.
The key is not to choose the longest synonym list. It is to choose the most precise word for the situation. Understanding these differences will make your writing clearer, more natural, and more accurate.
Oliver Grant is a vocabulary researcher who focuses on uncovering the subtle differences between similar words. He specializes in synonyms, antonyms, and contextual usage, helping readers choose the most accurate word in any situation. His content is designed for writers, bloggers, and students who want to elevate their language skills and write with precision.
