rationalize

Concise Oxford English Dictionary © 2008 Oxford University Press:
rationalize /ˈraʃnəlʌɪz/ (or rationalise)

▶verb

• 1 attempt to justify (an action or attitude) with logical reasoning.

• 2 Brit. make (a company or industry) more efficient by dispensing with superfluous personnel or equipment.

  ■ reorganize (a process or system) so as to make it more logical and consistent.

• 3 Mathematics convert to a rational form.

– derivatives
rationalization noun,
rationalizer noun.