The Collaborative International Dictionary of English v.0.48:

Sermonize \Ser"mon*ize\, v. i. [imp. & p. p. Sermonized; p.
   pr. & vb. n. Sermonizing.]
   1. To compose or write a sermon or sermons; to preach.
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   2. To inculcate rigid rules. [R.] --Chesterfield.
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