sermon

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A religious discourse, especially one delivered as part of a service.
• noun An often lengthy and tedious speech of reproof or exhortation.

from The Century Dictionary.

• noun A speech, discourse, or writing.
• noun A discourse delivered by a clergyman, licentiate, or other person, for the purpose of religious instruction and edification, during divine service, usually founded upon or in elucidation of some text or passage of Scripture.
• noun Hence—
• noun A written dissertation of similar character.
• noun Any serious address on a moral or religious theme, whether delivered or published, by a clergyman or by a layman: as, a lay sermon.
• noun Any serious exhortation, counsel, or reproof: usually in an admonitory or reprobatory sense.
• noun Synonyms Sermon, Homily, Exhortation. Sermon is the standard word for a formal address on a religious subject, founded upon a text of Scripture. Homily is an old word for the same thing, especially for an exposition of doctrine, but is now more often used for a conversational address, shorter than a sermon, of much directness and seriousness, perhaps upon a point of duty. Exhortation is occasionally used for a religious address appealing to one's conscience or calling one to the performance of duty in general or some specific duty.
• To discourse of, as in a sermon.
• To tutor; lecture.
• To compose or deliver a sermon; discourse.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb obsolete To speak; to discourse; to compose or deliver a sermon.
• transitive verb obsolete To discourse to or of, as in a sermon.
• transitive verb Poetic To tutor; to lecture.
• noun obsolete A discourse or address; a talk; a writing.
• noun Specifically, a discourse delivered in public, usually by a clergyman, for the purpose of religious instruction and grounded on some text or passage of Scripture.
• noun Hence, a serious address; a lecture on one's conduct or duty; an exhortation or reproof; a homily; -- often in a depreciatory sense.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun religious discourse; a written or spoken address on a religious or moral matter
• noun a lengthy speech of reproval
• verb poetic, obsolete To discourse to or of, as in a sermon.
• verb poetic, obsolete To tutor; to lecture.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an address of a religious nature (usually delivered during a church service)
• noun a moralistic rebuke