Source : Webster's Revised Unabridged Dictionary (1913)

Extenuation \Ex*ten`u*a"tion\, n. [L. extenuatio: cf. F.
   ext['e]nuation.]
   The act of axtenuating or the state of being extenuated; the
   act of making thin, slender, or lean, or of palliating;
   diminishing, or lessening; palliation, as of a crime;
   mitigation, as of punishment.

         To listen . . . to every extenuation of what is evil.
                                                  --I. Taylor.

Source : WordNet®

extenuation
     n 1: a partial excuse to mitigate censure; an attempt to
          represent an offense as less serious than it appears by
          showing mitigating circumstances [syn: {mitigation}]
     2: to act in such a way as to cause an offense to seem less
        serious [syn: {mitigation}, {palliation}]