2. 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. This our life exempt from public haunts finds tongues in trees, books in the running brooks, sermons in stones and good in everything. (Shak) His preaching much, but more his practice, wrought, A living sermon of the truths he taught. (Dryden)
Origin: OE. Sermoun, sermun, F. Sermon, fr. L. Sermo, -onis, a speaking, discourse, probably fr. Serer, sertum, to join, connect; hence, a connected speech. See Series.