Postil | Webster's Dictionary (1865)

Pŏs'til, n.

noun

n. [Fr. postille, apostille, Sp. postila, It., Pg., & L. Lat. postilla, from Lat. post illa (sc. verba). Cf. Apostil.]

Originally, a note in the margin of the Bible, so called because written after the text; hence, a marginal note.
(Rom. Cath. & Lutheran Churches.) A homily to be read in public by clergymen who are incompetent to teach; as, the first postils were composed by order of Charlemagne; Luther also wrote postils; the books of homilies in the English church were postils under another name. Murdock.

Their studies [those of the clergy] had reached no further than the breviary, the postils, &c. Milward.

Pŏs'til, v. i.

verbintransitive

v. i. To write postils, or marginal notes; to comment; to postillate. [Obs.]

Pŏs'til, v. t.

verbtransitive

v. t. [It. & L. Lat. postillare, Pr. & Pg. postillar, Sp. postilar, Fr. apostiller. See supra.] To write, as a marginal note; to gloss; to illustrate with marginal notes. [Rare.] Bacon.