[ ree-zuhn ]
See synonyms for: reasonreasonedreasoningreasons on

  1. a basis or cause, as for some belief, action, fact, event, etc.: the reasons for declaring war.

  2. a statement presented in justification or explanation of a belief or action: I dare you to give me one good reason for quitting school!

  1. sufficient cause, as produced by a situation that makes an act, feeling, etc., obviously proper or appropriate: After the mess he made of our yard, we have good reason to look for another landscaper.

  2. the mental powers concerned with forming conclusions, judgments, or inferences: Effective leadership requires a person of reason.

  3. sound judgment; good sense.

  4. normal or sound powers of mind; sanity.

  5. Logic. a premise of an argument.

  6. Philosophy.

    • the faculty or power of acquiring intellectual knowledge, either by direct understanding of first principles or by argument.

    • the power of intelligent and dispassionate thought, or of conduct influenced by such thought.

    • Kantianism. the faculty by which the ideas of pure reason are created.

verb (used without object)
  1. to think or argue in a logical manner.

  2. to form conclusions, judgments, or inferences from facts or premises.

  1. to urge reasons which should determine belief or action.

verb (used with object)
  1. to think through logically, as a problem (often followed by out).

  2. to conclude or infer.

  1. to convince, persuade, etc., by reasoning.

  2. to support with reasons.

Idioms about reason

  1. bring (someone) to reason, to induce a change of opinion in (someone) through presentation of arguments; convince: The mother tried to bring her rebellious daughter to reason.

  2. by reason of, on account of; because of: He was consulted about the problem by reason of his long experience.

  1. in / within reason, in accord with reason; justifiable; proper: She tried to keep her demands in reason.

  2. stand to reason, to be clear, obvious, or logical: With such an upbringing it stands to reason that the child will be spoiled.

  3. with reason, with justification; properly: The government is concerned about the latest crisis, and with reason.

Origin of reason

First recorded in 1175–1225; Middle English resoun, reisun (noun), from Old French reisun, reson, from Latin ratiōn- (stem of ratiō ) ratio

synonym study For reason

1. Reason, cause, motive are terms for a circumstance (or circumstances) which brings about or explains certain results. A reason is an explanation of a situation or circumstance which made certain results seem possible or appropriate: The reason for the robbery was the victim's display of his money. The cause is the way in which the circumstances produce the effect, that is, make a specific action seem necessary or desirable: The cause was the robber's extreme need of money. A motive is the hope, desire, or other force which starts the action (or an action) in an attempt to produce specific results: The motive was to get money to buy food for his family.

usage note For reason

The construction reason is because is criticized in a number of usage guides: The reason for the long delays was because the costs greatly exceeded the original estimates. One objection to this construction is based on its redundancy: the word because (literally, by cause ) contains within it the meaning of reason; thus saying the reason is because is like saying “The cause is by cause,” which would never be said. A second objection is based on the claim that because can introduce only adverbial clauses and that reason is requires completion by a noun clause. Critics would substitute that for because in the offending construction: The reason for the long delays in completing the project was that the costs. … Although the objections described here are frequently raised, reason is because is still common in almost all levels of speech and occurs often in edited writing as well.
A similar charge of redundancy is made against the reason why, which is also a well-established idiom: The reason why the bill failed to pass was the defection of three key senators.

Other words for reason

Other words from reason

  • rea·son·er, noun
  • non·rea·son, noun
  • non·rea·son·er, noun
  • outreason, verb (used with object)
  • sub·rea·son, noun

Words Nearby reason Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use reason in a sentence

British Dictionary definitions for reason


/ (ˈriːzən) /

  1. the faculty of rational argument, deduction, judgment, etc

  2. sound mind; sanity

  1. a cause or motive, as for a belief, action, etc

  2. an argument in favour of or a justification for something

  3. philosophy the intellect regarded as a source of knowledge, as contrasted with experience

  4. logic grounds for a belief; a premise of an argument supporting that belief

  5. by reason of because of

  6. in reason or within reason within moderate or justifiable bounds

  7. it stands to reason it is logical or obvious: it stands to reason that he will lose

  8. listen to reason to be persuaded peaceably

  9. reasons of State political justifications for an immoral act

  1. (when tr, takes a clause as object) to think logically or draw (logical conclusions) from facts or premises

  2. (intr usually foll by with) to urge or seek to persuade by reasoning

  1. (tr often foll by out) to work out or resolve (a problem) by reasoning

Origin of reason

C13: from Old French reisun, from Latin ratiō reckoning, from rērī to think

usage For reason

The expression the reason is because… should be avoided. Instead one should say either this is because… or the reason is that…

Derived forms of reason

  • reasoner, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with reason


see by reason of; in reason; it stands to reason; listen to reason; lose one's mind (reason); rhyme or reason; see reason; stand to reason; with reason.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.