RhymeZone: postil definitions

Definitions of postil:

noun: (archaic) A Bible commentary written in its margins.
noun: A marginal note.
noun: A short homily or commentary on a passage of Scripture.
noun: A collection of homilies.
verb: (transitive) To write marginal or explanatory notes on; to gloss.
verb: (intransitive) To write postils, or marginal notes; to comment; to postillate.

(Definitions from Wiktionary)