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

Keep scrolling for more

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.
See More

Recent Examples on the Web: Noun

The reason a submarine of any size would be helpful to the rescuers is because exiting the cave requires negotiating long stretches under water, and some of the young Thai players do not know how to swim. Ashley Wong, USA TODAY, "Elon Musk sends an 'escape pod' to help in Thailand cave rescue," 9 July 2018 That is a key reason that Fed officials expect to raise short-term rates twice more this year. Christopher Rugaber, Fox News, "US inflation reaches 2.9 percent in June, highest in 6 years," 13 July 2018 Is there a reason why there’s a size limit for portable chargers? Claire Wolters,, "Linc requires clear bags at tonight's Taylor Swift concert," 13 July 2018 There's a reason the bad guys are burning down the building, but it's explained away in about 30 seconds toward the end and doesn't matter anyway. Bill Goodykoontz, azcentral, "'Skyscraper:' Big, dumb and kind of fun, thanks to Dwayne Johnson and Neve Campbell," 12 July 2018 College costs have skyrocketed in the last decade, which may be a reason for the enrollment decline among middle-income students. Eric Stirgus, ajc, "Study: More middle-income students squeezed from top colleges," 12 July 2018 As for the familiarity, there was a reason for that. Josh Noel,, "Can craft brewers make good light beer? Our tasting pits them against Bud, Miller, Coors, more," 12 July 2018 That is a big reason why its share of the ETF market has sunk to less than 18% and it was overtaken in 2015 by Vanguard as the second largest provider, analysts say. Asjylyn Loder, WSJ, "Investors Win From ETF Price War," 12 July 2018 There's a reason that adult play exists in modern society, says Lynn Barnett, a professor of recreation, sports and tourism at the University of Illinois at Urbana-Champaign. Jennifer Wallace,, "Play Is Important For Adults, Too," 9 July 2018

Recent Examples on the Web: Verb

The real miracle of reading comprehension, AI experts said, is in reading between the lines: connecting concepts, reasoning with ideas and understanding implied messages that aren’t specifically outlined in the text. Drew Harwell, The Seattle Times, "AI’s ability to read is hailed as milestone, but there’s still long way to go," 21 Jan. 2018 Goodman says PPLs can reason not only about physics and logistics, but also about how people communicate, coping with tricky forms of expression such as hyperbole, irony, and sarcasm. Matthew Hutson, Science | AAAS, "How researchers are teaching AI to learn like a child," 24 May 2018 The findings show babies still too young to speak can reason and make rational deductions. Bret Stetka, Scientific American, "Babies Think Logically Before They Can Talk," 15 Mar. 2018 Theirs not to reason why, Theirs but to do and die, Into the valley of Death Rode the six hundred Why would a father ask his ever-expanding brood of what became 11 children to memorize a poem about war and slaughter? Kerry Kennedy, Time, "Kerry Kennedy: What My Father, RFK, Means Today," 31 May 2018 If that was done, Kelly reasoned, there would be no argument about equal protection — that is, the constitutional guarantee that all people be treated the same. Cary Spivak, Milwaukee Journal Sentinel, "Wisconsin Supreme Court takes up challenge to legality of state's caps on medical malpractice payments," 19 Apr. 2018 Many in China still cling to the hope that he can be reasoned with. The Economist, "As its trade tussle with America heats up, China is on the back foot," 5 July 2018 Limbo, some medieval theologians reasoned, must have been where Jesus went in the three days between his death and resurrection to free the virtuous souls who had perished before him but not had the opportunity to be redeemed by his sacrifice. John Hooper, WSJ, "How a $30 Million Renaissance Masterpiece Was Found," 21 May 2018 At a time when the country seems to have forgotten how to have reasoned argument, these participants are displaying skills their coaches say are even better than adult politicians’. Christa Case Bryant, The Christian Science Monitor, "Need help winning an argument? Ask a Kansas high-schooler.," 11 Apr. 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.

See More

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

Keep scrolling for more

Learn More about reason

Statistics for reason

Last Updated

18 Sep 2018

Look-up Popularity

Time Traveler for reason

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

See more words from the same century

Keep scrolling for more

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

Keep scrolling for more

Comments on reason

What made you want to look up reason? Please tell us where you read or heard it (including the quote, if possible).


the setting in which something occurs

Get Word of the Day daily email!

Test Your Vocabulary

Musical Words Quiz

  • gramophone
  • Which word describes a musical performance marked by the absence of instrumental accompaniment?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!