rationalize

American  

[rash-uh-nl-ahyz, rash-nl-ahyz] / ˈræʃ ə nlˌaɪz, ˈræʃ nlˌaɪz /

especially British, rationalise

verb (used with object)

rationalized, rationalizing

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.

3. to make rational or conformable to reason.

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

5. Mathematics. to eliminate radicals from (an equation or expression).

   to rationalize the denominator of a fraction.

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

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verb (used without object)

rationalized, rationalizing

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.

rationalize British  

/ ˈræʃənəˌlaɪz /

verb

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)

3. to apply logic or reason to (something)

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

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

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Usage

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 Word Forms

• nonrationalized adjective
• overrationalize verb
• rationalization noun
• rationalizer noun
• semirationalized adjective
• unrationalized adjective
• unrationalizing adjective

Etymology

Origin of rationalize

First recorded in 1810–20; rational + -ize

Explanation

Rationalize means to justify by developing a rationale, or a set of reasons for something. You could rationalize cutting school, saying your classes are boring, but you are still doing what you shouldn't be doing. Rationalize can also mean reorganizing along rational lines––a watchmaker's shop might be set up in a totally illogical way that made sense only to the old owner, whose children will rationalize the shop's organization once the old man dies.

Example Sentences

Securities and Exchange Commission Chairman Paul Atkins in a presentation mostly aimed at showing that the agencies would harmonize their rules to promote cryptocurrency innovation and rationalize margin collateral requirements in securities markets.

From Barron's • Jan. 31, 2026

If it’s just in your head, it’s too easy to rationalize exceptions.

From MarketWatch • Jan. 28, 2026

Kyiv also wants to become more self-reliant through domestically produced weapons that will also help rationalize the hodgepodge of donated Western equipment it currently uses.

From The Wall Street Journal • Dec. 31, 2025

Dahlia Lithwick: There is a very human propensity, especially in times of crisis, to normalize and rationalize and temporize.

From Slate • Dec. 17, 2025

I rationalize that none of the physical things matter so much.

From "I Am the Messenger" by Markus Zusak

Related Words

• justify