Source : Webster's Revised Unabridged Dictionary (1913)

Excusatory \Ex*cus"a*to*ry\, a.
   Making or containing excuse or apology; apologetical; as, an
   excusatory plea.

Source : WordNet®

excusatory
     adj : offering or expressing apology; "an apologetic note"; "an
           apologetic manner" [syn: {apologetic}] [ant: {unapologetic}]