colloquial (frequently depreciative).
intransitive. To preach, esp. in a self-righteous or tedious way.
1776 S. J. Pratt Liberal Opinions III. liv. 69 He wrote obstinately on,..preachifying, till he piously picked my pocket of above a hundred and fifty guineas.
1800 E. Hamilton Mem. Mod. Philosophers II. iv. 45 From the manner in which she preachified, I should suppose her to be a Methodist.
1869 D. M. Mulock Woman's Kingdom II. 137 I am going to preachify in earnest; and..it is about a very serious thing.
1903 Ottumwa (Iowa) Daily Courier 2 Apr. 5/4 The Fays are content to simply set people thinking, without any desire to preachify or exploit any special doctrine or theory.
1964 J. Rhys Lett. (1984) 271 I have a great and deep admiration for the Brontë sisters (though Charlotte did preachify sometimes).
2001 Palm Beach (Florida) Post (Nexis) 15 Jan. 4 e Rhyant has become a fund-raiser as well as a minister, but he's a preacher who doesn't preachify.