Source : Webster's Revised Unabridged Dictionary (1913)

Inculpable \In*cul"pa*ble\, a. [L. inculpabilis: cf. F.
   incupable.]
   Faultless; blameless; innocent. --South.

         An innocent and incupable piece of ignorance.
                                                  --Killingbeck.

Source : WordNet®

inculpable
     adj : free of guilt; not subject to blame; "has lived a blameless
           life"; "of irreproachable character"; "an unimpeachable
           reputation" [syn: {blameless}, {irreproachable}, {unimpeachable}]