Source : Webster's Revised Unabridged Dictionary (1913)

Sermonic \Ser*mon"ic\, Sermonical \Ser*mon"ic*al\, a.
   Like, or appropriate to, a sermon; grave and didactic. [R.]
   ``Conversation . . . satirical or sermonic.'' --Prof. Wilson.
   ``Sermonical style.'' --V. Knox.