Source : Webster's Revised Unabridged Dictionary (1913)

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.

         The lord archbishop . . . made a long oration. --Bacon.

   Syn: Address; speech. See {Harangue}.

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

Source : WordNet®

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