[rash-uh-nl-ahyz, rash-nl-ahyz]

verb (used with object), ra·tion·al·ized, ra·tion·al·iz·ing.

verb (used without object), ra·tion·al·ized, ra·tion·al·iz·ing.

to invent plausible explanations for acts, opinions, etc., that are actually based on other causes: He tried to prove that he was not at fault, but he was obviously rationalizing.
to employ reason; think in a rational or rationalistic manner.

Also especially British, ra·tion·al·ise.

Origin of rationalize

First recorded in 1810–20; rational + -ize
Related formsra·tion·al·i·za·tion, nounra·tion·al·iz·er, nounnon·ra·tion·al·i·za·tion, nounnon·ra·tion·al·ized, adjectiveo·ver·ra·tion·al·i·za·tion, nouno·ver·ra·tion·al·ize, verb, o·ver·ra·tion·al·ized, o·ver·ra·tion·al·iz·ing.sem·i·ra·tion·al·ized, adjectiveun·ra·tion·al·ized, adjectiveun·ra·tion·al·iz·ing, adjective

Usage note

Although rationalize retains its principal 19th-century senses “to make conformable to reason” and “to treat in a rational manner,” 20th-century psychology has given it the now more common meaning “to ascribe (one's acts, opinions, etc.) to causes that seem reasonable but actually are unrelated to the true, possibly unconscious causes.” Although the possibility of ambiguity exists, the context will usually make clear which sense is intended.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rationalization

Contemporary Examples of rationalization

Historical Examples of rationalization

  • But the Zen's question, even my rationalization of my reaction to it, had given me a chill.


    Jerome Bixby

  • For no rationalization in the universe would allow him to define her as human.

    The Lani People

    J. F. Bone

  • Rationalization and ratiocination merged in her mind very readily.

    Emma Goldman

    Charles A. Madison

  • It is not the rationalization of Jewish dogma that he is interested in, nor the reconciliation of religion and philosophy.

  • Juristically this seems to be a rationalization of the Roman innominate contract.

British Dictionary definitions for rationalization




to justify (one's actions, esp discreditable actions, or beliefs) with plausible reasons, esp after the event
psychol to indulge, often unchallenged, in excuses for or explanations of (behaviour about which one feels uncomfortable or guilty)
to apply logic or reason to (something)
to eliminate unnecessary equipment, personnel, or processes from (a group of businesses, factory, etc), in order to make it more efficient
(tr) maths to eliminate one or more radicals without changing the value of (an expression) or the roots of (an equation)
Derived Formsrationalization or rationalisation, nounrationalizer or rationaliser, 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

Word Origin and History for rationalization

1825, "a rendering rational," from rationalize + -ation. Psychological use is from 1908.

Of the three works now on our table, the two which we have placed first have these laudable objects in view; an improvement on the former versions of the Psalms as compositions, and the rationalization, if we may so speak, of our Church psalmody. ["The British Critic," London, Jan.-June 1825]



1767, "explain in a rational way, make conformable to reason," from rational + -ize. In the psychological sense of "to give an explanation that conceals true motives" it dates from 1922. Related: Rationalized; rationalizing.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for rationalization




To make rational.
To devise self-satisfying but false or inconsistent reasons for one's behavior, especially as an unconscious defense mechanism through which irrational acts or feelings are made to appear rational to oneself.
Related formsra′tion•al•i•zation (-lĭ-zāshən) n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.