rationalize

American  

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

especially British, rationalise

verb (used with object)

rationalizes, present (3rd person singular) rationalized, past participle, past rationalizing present participle

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)

rationalizes, present (3rd person singular) rationalized, past participle, past rationalizing present participle

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

Derived Forms

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

Conjugated Forms

Present

• has rationalized
  perfect 3rd person singular
• have rationalized
  perfect
• are rationalizing
  progressive
• has been rationalizing
  perfect progressive 3rd person singular
• have been rationalizing
  perfect progressive
• rationalizing
  participle
• is rationalizing
  progressive 3rd person singular
• rationalizes
  singular 3rd person
• am rationalizing
  progressive 1st person singular

Past

• had rationalized
  perfect
• was rationalizing
  progressive singular
• were rationalizing
  progressive plural
• had been rationalizing
  perfect progressive
• rationalized
  participle
• rationalized
  simple

Future

• will rationalize
  simple
• will have rationalized
  perfect
• will be rationalizing
  progressive
• will have been rationalizing
  perfect progressive

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

“In all of the history of money bail there has never been an attempt to rationalize the money amounts. The money amounts of the bonds are literally picked out of the air.”

From Los Angeles Times • May 29, 2026

"Our findings allowed us to rationalize the critical role of engineering the hydrogen-bond network at the catalyst/electrolyte interface in designing high-efficiency, low-cost AEMWEs," Wu said.

From Science Daily • May 18, 2026

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

She was missing Johnny so terribly and thinking so, to rationalize his not being there.

From "A Tree Grows in Brooklyn" by Betty Smith

Related Words

• justify