Oration, n.
Etymology: [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.
1 other Webster entry under this spelling
Oration, v. i.
To deliver an oration. Donne.
Shades of meaning
Fernald has no entry of its own for oration; he lists it under speech.
Where he writes about it:
A speech may be the delivering of one's sentiments in the simplest way; an oration is an elaborate and prepared speech; a harangue is a vehement appeal to passion, or a speech that has something disputatious and combative in it. — from speech