15 letters · 24 points in Scrabble
noun the cognitive process of making something seem consistent with or based on reason
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 (mathematics) the simplification of an expression or equation by eliminating radicals without changing the value of the expression or the roots of the equation
originFirst attested in 1831. From French rationalisation, equivalent to rational + -ization or rationalize + -ation.
Etymology from Wiktionary, CC BY-SA 3.0