The Collaborative International Dictionary of English v.0.48:

Oration \O*ra"tion\, v. i.
   To deliver an oration. --Donne.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Oration \O*ra"tion\, n.[L. oratio, fr. orare to speak, utter,
   pray. See Oral, Orison.]
   An elaborate discourse, delivered in public, treating an
   important subject in a formal and dignified manner;
   especially, a discourse having reference to some special
   occasion, as a funeral, an anniversary, a celebration, or the
   like; -- distinguished from an argument in court, a popular
   harangue, a sermon, a lecture, etc.; as, Webster's oration at
   Bunker Hill.
   [1913 Webster]

         The lord archbishop . . . made a long oration. --Bacon.
   [1913 Webster]

   Syn: Address; speech. See Harangue.
        [1913 Webster]

WordNet (r) 3.0 (2006):

oration
    n 1: an instance of oratory; "he delivered an oration on the
         decline of family values"