Source : Webster's Revised Unabridged Dictionary (1913)

Accreditation \Ac*cred`i*ta"tion\, n.
   The act of accrediting; as, letters of accreditation.

Source : WordNet®

accreditation
     n : the act of granting credit or recognition (especially with
         respect to educational institution that maintains
         suitable standards); "a commission is responsible for the
         accreditation of medical schools"