Extenuation

[Sarah]

The act of axtenuating or the state of being extenuated; theact of making thin, slender, or lean, or of palliating; diminishing,or lessening; palliation, as of a crime; mitigation, as ofpunishment.To listen . . . to every extenuation of what is evil. I. Taylor.

[Vania]

the fact of judging a wrong act less seriously by giving reasons for it:

[Dorothey Allen]

The action of lessening the seriousness of guilt or an offense.