[ rash-uh-nl-ahyz, rash-nl-ahyz ]
See synonyms for: rationalizerationalizingrationalization on Thesaurus.com

verb (used with object),ra·tion·al·ized, ra·tion·al·iz·ing.
  1. to ascribe (one's acts, opinions, etc.) to causes that superficially seem reasonable and valid but that actually are unrelated to the true, possibly unconscious and often less creditable or agreeable causes.

  2. to remove unreasonable elements from.

  1. to make rational or conformable to reason.

  2. to treat or explain in a rational or rationalistic manner.

  3. Mathematics. to eliminate radicals from (an equation or expression): to rationalize the denominator of a fraction.

  4. Chiefly British. to reorganize and integrate (an industry).

verb (used without object),ra·tion·al·ized, ra·tion·al·iz·ing.
  1. 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.

  2. to employ reason; think in a rational or rationalistic manner.

Origin of rationalize

First recorded in 1810–20; rational + -ize
  • Also especially British, ra·tion·al·ise .

usage note For rationalize

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.

Other words from rationalize

  • ra·tion·al·i·za·tion [rash-uh-nl-ahy-zey-shuhn, rash-nl-] /ˌræʃ ə nl aɪˈzeɪ ʃən, ˌræʃ nl-/ especially British, ra·tion·al·i·sa·tion, noun
  • ra·tion·al·iz·er; especially British, ra·tion·al·is·er, noun
  • non·ra·tion·al·ized; especially British, non·ra·tion·al·ised, adjective
  • o·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; especially British, sem·i·ra·tion·al·ised, adjective
  • un·ra·tion·al·ized; especially British, un·ra·tion·al·ised, adjective
  • un·ra·tion·al·iz·ing; especially British, un·ra·tion·al·is·ing, adjective

Words Nearby rationalize

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use rationalize in a sentence

British Dictionary definitions for rationalize



/ (ˈræʃənəˌlaɪz) /

  1. to justify (one's actions, esp discreditable actions, or beliefs) with plausible reasons, esp after the event

  2. psychol to indulge, often unchallenged, in excuses for or explanations of (behaviour about which one feels uncomfortable or guilty)

  1. to apply logic or reason to (something)

  2. to eliminate unnecessary equipment, personnel, or processes from (a group of businesses, factory, etc), in order to make it more efficient

  3. (tr) maths to eliminate one or more radicals without changing the value of (an expression) or the roots of (an equation)

Derived forms of rationalize

  • rationalization or rationalisation, noun
  • rationalizer 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