Webster's Revised Unabridged Dictionary · 1913

Sermonize

Sermonize , intransitive verb

1.
To compose or write a sermon or sermons; to preach.
2.
To inculcate rigid rules. [Rare] — Chesterfield

Sermonize , transitive verb

To preach or discourse to; to affect or influence by means of a sermon or of sermons. [Rare]
Which of us shall sing or sermonize the other fast asleep? — Landor