reason

1 of 2

noun

rea·​son ˈrē-zᵊn 

1

a

: a statement offered in explanation or justification

gave reasons that were quite satisfactory

b

: a rational ground or motive

a good reason to act soon

c

: the thing that makes some fact intelligible : cause

the reason for earthquakes

the real reason why he wanted me to stay

—Graham Greene

d

: a sufficient ground of explanation or of logical defense

especially : something (such as a principle or law) that supports a conclusion or explains a fact

the reasons behind her client's action

2

a(1)

: the power of comprehending, inferring, or thinking especially in orderly rational ways : intelligence

(2)

: proper exercise of the mind

(3)

: sanity

b

: the sum of the intellectual powers

3

archaic : treatment that affords satisfaction

reason

2 of 2

verb

reasoned; reasoning ˈrēz-niŋ 

ˈrē-zᵊn-iŋ

intransitive verb

1

: to use the faculty of reason so as to arrive at conclusions

2

a

: to talk with another so as to influence actions or opinions

can't reason with them

b

obsolete : to take part in conversation, discussion, or argument

transitive verb

1

: to discover, formulate, or conclude by the use of reason

a carefully reasoned analysis

2

: to persuade or influence by the use of reason

3

archaic : to justify or support with reasons

reasoner

ˈrēz-nər 

ˈrē-zᵊn-ər

noun

Phrases

in reason

: rightly, justifiably

within reason

: within reasonable limits

with reason

: with good cause

Synonyms

Noun

• explanation
• argument

Verb

• understand
• derive
• decide
• think

Choose the Right Synonym for reason

think, cogitate, reflect, reason, speculate, deliberate mean to use one's powers of conception, judgment, or inference.

think is general and may apply to any mental activity, but used alone often suggests attainment of clear ideas or conclusions.

teaches students how to think

cogitate implies deep or intent thinking.

cogitated on the mysteries of nature

reflect suggests unhurried consideration of something recalled to the mind.

reflecting on fifty years of married life

reason stresses consecutive logical thinking.

able to reason brilliantly in debate

speculate implies reasoning about things theoretical or problematic.

speculated on the fate of the lost explorers

deliberate suggests slow or careful reasoning before forming an opinion or reaching a conclusion or decision.

the jury deliberated for five hours

Examples of reason in a Sentence

Noun

I gave a reason for my absence.

Is there a reason for your strange behavior?

There is a reason why they don't want to come.

I can't give you the report for the simple reason that it isn't yet finished.

She explained her reasons for deciding to change jobs.

He wanted to know the reason for their decision.

Give me one good reason why I should believe you.

For obvious reasons, we can't do that yet.

For reasons of space, some of the charts and graphs have been omitted from the article.

She resigned for personal reasons.

Verb

He lost the ability to reason.

He reasoned that both statements couldn't be true.

She reasoned that something must be wrong.

Recent Examples on the Web

Noun

His present is extremely bright, and there’s no reason to expect near term slippage. —Tony Blengino, Forbes.com, 1 July 2025

And in 2025, there’s reason to think such a facet of the Panthers’ offense got better. —Alex Zietlow, Charlotte Observer, 1 July 2025

Verb

If a company has the ability to drive growing earnings over the long term, investors will eventually recognize the success and bid up the stock price, Buffett reasoned in his 1987 letter to Berkshire shareholders. —Ryan Ermey, CNBC, 30 June 2025

One promising approach is the use of AI agents—autonomous systems that can reason, act and drive outcomes across the sales cycle. —Anand Shah, Forbes.com, 30 June 2025

Word History

Etymology

Noun

Middle English resoun, from Anglo-French raisun, from Latin ration-, ratio "reckoning, calculation, explanation," from reri "to calculate, think;" probably akin to Goth rathjo "account, explanation"

First Known Use

Noun

13th century, in the meaning defined at sense 1a

Verb

15th century, in the meaning defined at intransitive sense 2b

Phrases Containing reason

• age of reason
• by reason of
• deaf to reason
• for no good reason
• for one reason or another
• for some reason or another
• for some reason or other
• for some strange reason
• for some/whatever reason
• for the simple reason that
• it stands to reason
• lose one's reason
• open to reason
• reason out
• reason with
• rhyme or reason
• stand to reason
• voice of reason
• without reason

Rhymes for reason

• season
• seizin
• treason
• milesian
• partizan
• postseason
• preseason
• unreason

Kids Definition

reason

1 of 2 noun

rea·​son ˈrēz-ᵊn 

1

a

: a statement given to explain a belief or act

gave a reason for my absence

b

: a good basis

reasons for thinking life may exist on other planets

c

: the thing that makes some fact understandable : cause

wanted to know the reason for earthquakes

2

a

: the power to think : intelligence

b

: a sound mind

reason

2 of 2 verb

reasoned; reasoning ˈrēz-niŋ 

-ᵊn-iŋ

1

: to talk with another in order to cause a change of mind

reason with someone

2

a

: to use the power of reason

b

: to state or conclude by use of reason

reasoned that both statements couldn't be true

Legal Definition

reason

noun

rea·​son

1

: an underlying ground, justification, purpose, motive, or inducement

required to provide reasons for the termination in writing

2

a

: the faculty of comprehending, inferring, or distinguishing especially in a fair and orderly way

b

: the proper and sane exercise of the mind