rea·​son | \ˈrē-zᵊn \

Definition of reason 

(Entry 1 of 2)

1a : 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 : 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

d : the thing that makes some fact intelligible : cause the reason for earthquakes the real reason why he wanted me to stay— Graham Greene

2a(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

in reason within reason

: within reasonable limits

with reason

: with good cause


reasoned; reasoning\ˈrēz-​niŋ, ˈrē-​zᵊn-​iŋ \

Definition of reason (Entry 2 of 2)

intransitive verb

1a obsolete : to take part in conversation, discussion, or argument

b : to talk with another so as to influence actions or opinions can't reason with them

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

transitive verb

1 archaic : to justify or support with reasons

2 : to persuade or influence by the use of reason

3 : to discover, formulate, or conclude by the use of reason a carefully reasoned analysis

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Other Words from reason


reasoner \ˈrēz-​nər, ˈrē-​zᵊn-​ər \ noun

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


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.


He lost the ability to reason. He reasoned that both statements couldn't be true. She reasoned that something must be wrong.
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Recent Examples on the Web: Noun

Tesla didn’t gave a reason for his departure, although the company said planning for the transition began in July. Rebecca Ballhaus, WSJ, "Tesla Replaces General Counsel With Seasoned Trial Lawyer," 7 Dec. 2018 Here’s a few reasons why Lyft’s decision is the right one. Theodore Schleifer, Recode, "Why Lyft had to beat Uber to an IPO filing," 6 Dec. 2018 But this season, one artist had fans talking for a much different reason. Kelly O'sullivan, Country Living, "Why Fans of 'The Voice' Can’t Stop Talking About Matt Johnson’s Blind Audition," 21 Oct. 2018 There's no reason to believe this process is restricted to our planet. Mike Wall,, "Jupiter Moon Europa's Jagged Ice Towers Could Imperil Robot Landers," 8 Oct. 2018 McConnell said, ignoring that Trump seems to have no reason for appointing Whitaker to replace Sessions beyond his hostility to Mueller. Aaron Rupar, Vox, "Republican group runs “protect Mueller” ad on Trump’s favorite show," 14 Nov. 2018 But that’s not the only reason to opt for the Shield TV. Ian Paul, PCWorld, "Nvidia's Shield TV, the best media streamer for enthusiasts, hits its lowest price yet," 7 Nov. 2018 For this reason, the House Beautiful Whole Home Project sought to make a concept home that was truly a sanctuary of self-care—for every member of your family. Taylor Mead, House Beautiful, "If You Have A Pet, You Need This Doggy Room," 25 Oct. 2018 For that reason, some argue that Washington might have to consider a compromise with Riyadh — a plan that wouldn’t curb the country’s path to a nuclear bomb — in order to sign a deal. Alex Ward, Vox, "Exclusive: House Democrat to introduce new bill punishing Saudi Arabia over Khashoggi," 9 Nov. 2018

Recent Examples on the Web: Verb

The school's new policy is spearheaded by High School Principal Mark Hayes, who reasoned the numerous shootings in the country led him to the decision to arm his employees. Christine Coppa, Good Housekeeping, "Oklahoma School District Is Allowing Its Teachers to Bear Arms," 7 Feb. 2016 Mike attempts to reason with Ryan, but can't seem to find common ground. Emma Dibdin, Country Living, "5 Moments From the 'Last Man Standing' Premiere That We Can't Stop Talking About," 29 Sep. 2018 And if that’s not reason enough to drop $1,000 on a new phone, Note 9 pre-orders through can also score a whopping 15,000 V-Bucks as a bonus. Michael Simon, PCWorld, "Samsung celebrates the Galaxy Note 9 launch with Fortnite beta access and 15,000 free V-Bucks," 9 Aug. 2018 Because it’s considered invasive and therefore plentiful, Zurkow reasoned. Zia Ur-rehman, The Seattle Times, "How record heat has wreaked havoc on four continents," 31 July 2018 Dorfman reasoned that a semimonthly benefit would more closely mirror the normal financial budgeting of SNAP recipients in working families. Nedra Rhone, ajc, "Study: Minority of SNAP recipients spend benefits early in the month," 10 July 2018 Such a fight could lead to a dicier path to confirmation through a narrow Senate majority, as well as more difficult midterm campaigns for a few Republicans, some of those people reasoned. Peter Nicholas, WSJ, "Trump Zeroes In on Supreme Court Pick," 6 July 2018 In a universe that had been around for some 14 billion years, and in that time developed more than a billion trillion stars, Fermi reasoned there simply must be other intelligent civilizations out there. Liv Boeree, Vox, "Why haven’t we found aliens yet?," 3 July 2018 The man who escaped the courthouse was guilty of rape, Brady reasoned. Michael Kiefer, azcentral, "Serial rapist to be sentenced after authorities solve name mystery," 2 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reason.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of reason


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


15th century, in the meaning defined at intransitive sense 1a

History and Etymology for reason


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

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Last Updated

11 Dec 2018

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The first known use of reason was in the 13th century

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More Definitions for reason



English Language Learners Definition of reason

 (Entry 1 of 2)

: a statement or fact that explains why something is the way it is, why someone does, thinks, or says something, or why someone behaves a certain way

: a fact, condition, or situation that makes it proper or appropriate to do something, feel something, etc.

: the power of the mind to think and understand in a logical way



English Language Learners Definition of reason (Entry 2 of 2)

: to think in a logical way

: to form (a conclusion or judgment) by thinking logically


rea·​son | \ˈrē-zᵊn \

Kids Definition of reason

 (Entry 1 of 2)

1 : a statement given to explain a belief or an act My parents gave a reason for my absence.

2 : a fact that makes something right or fair to do I have reasons for what I did.

3 : cause entry 1 sense 1 The child wanted to know the reason for rain.

4 : the power to think and understand in a logical way

5 : a fair and sensible way of thinking about something He won't listen to reason.


reasoned; reasoning

Kids Definition of reason (Entry 2 of 2)

1 : to think in a logical way

2 : to talk with another in a sensible way so as to influence his or her actions or opinions “It's a fear you can't be … reasoned out of.”— Kate DiCamillo, Because of Winn-Dixie

3 : to state or ask logically How, I reasoned, could such a thing happen?



Legal Definition of reason 

1 : an underlying ground, justification, purpose, motive, or inducement required to provide reasons for the termination in writing

2a : the faculty of comprehending, inferring, or distinguishing especially in a fair and orderly way

b : the proper and sane exercise of the mind

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More from Merriam-Webster on reason

Rhyming Dictionary: Words that rhyme with reason

Thesaurus: All synonyms and antonyms for reason

Spanish Central: Translation of reason

Nglish: Translation of reason for Spanish Speakers

Britannica English: Translation of reason for Arabic Speakers Encyclopedia article about reason

Comments on reason

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a nest or breeding place

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