The Collaborative International Dictionary of English v.0.48:

Postil \Pos"til\, v. i. [imp. & p. p. Postiled (?) or
   Postilled; p. pr. & vb. n. Postiling or Postilling.]
   To write postils, or marginal notes; to comment; to
   postillate.
   [1913 Webster]

         Postiling and allegorizing on Scripture. --J. H.
                                                  Newman.
   [1913 Webster]