v. ra·tion·al·ized, ra·tion·al·iz·ing, ra·tion·al·iz·es
1. To explain rationally: “Philosophy ... is essentially the endeavor of the human mind to rationalize the universe” (Francis E. Abbot).
a. To attempt to justify (one's behavior) by providing reasons that obscure one's actual motives: rationalized cheating on his taxes as being a form of political protest.
b. To dismiss or minimize the significance of (something) by means of an explanation or excuse: “He could not rationalize the loss of some thirty thousand American lives in an unsuccessful war” (Robert Dallek).
a. To make (a business or process, for example) more efficient, as by reducing costs or introducing modern methods.
b. To terminate the employment of (workers) in an effort to improve efficiency.
4. Mathematics To remove radicals, such as from a denominator, without changing the value of (an expression) or roots of (an equation).
1. To think in a rational or rationalistic way.
2. To rationalize one's behavior.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.