verb

• (intransitive) To speak in the manner of a sermon; to preach; to propagate one's morality or opinions with speech.
  "And doe not our Prelates thus, when […] they disgrace and traduce Preaching, calling it in scorne, Sermonizing?"
• (transitive) To preach a sermon to (somebody); to give (somebody) instruction or admonishment on the basis of one's morality or opinions.
  "He wishes, I suppose, to sermonize me: but I shall not give him an opportunity—"
• (transitive) To say in the manner of a sermon or lecture.
  "“Children, children! Woe, how you do sin!” Mrs. Kavarsky sermonized. “Come now, obey an older person […]”"
• (intransitive) To inculcate rigid rules.
  "If you consider my letters in their true light as conveying to you the advice of a Friend, who sincerely wishes you happiness, and desires to promote your pleasures, you will both read and attend them; but, if you consider them in their opposite, and very false light, as the dictates of a morose and sermonizing Father, I am sure they will be not only unattended to, but unread."