rationalization

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act, process, or practice of rationalizing.
• noun An instance of rationalizing.

from The Century Dictionary.

• noun The act of rationalizing; a making rational or intelligible; subjection to rational tests or principles.
• noun In algebra, the process of clearing an equation from radical signs. Also spelled rationalisation.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act or process of rationalizing.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The process, or result of rationalizing.
• noun A statement of one's motives, or of the causes of some event.
• noun A reorganization of a company or organization in order to improve its efficiency.
• noun psychiatry The concealment of true motivation in some non-threatening way.
• noun mathematics The simplification of an expression without changing its value.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (mathematics) the simplification of an expression or equation by eliminating radicals without changing the value of the expression or the roots of the equation
• noun the organization of a business according to scientific principles of management in order to increase efficiency
• noun (psychiatry) a defense mechanism by which your true motivation is concealed by explaining your actions and feelings in a way that is not threatening
• noun systematic organization; the act of organizing something according to a system or a rationale
• noun the cognitive process of making something seem consistent with or based on reason