# rationalize

/ˈɹæʃənəˌɫaɪz/ (US) · CEFR C1 · Verb

Source: https://englishreference.com/word/rationalize
Updated: 2026-05-19

## Definition

to explain something in a logical way, or to make a situation seem reasonable even if it is not. In math, it means removing a square root or other radical from the bottom of a fraction.

For teachers: to provide a logical explanation for a situation or to justify a belief or action. In a mathematical context, it refers to the process of removing a radical from the denominator of a fraction by multiplying the numerator and denominator by the same radical.

## Examples

- The company tried to rationalize the high prices by saying they were necessary for quality.
- To rationalize the denominator of the fraction, you multiply both the top and bottom by the square root of two.
- The government attempted to rationalize the sudden increase in fuel taxes by citing the need for infrastructure development and environmental protection.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.