Emily Dickinson Lexicon

RU'BRIC, n. [Fr. rubrique; L. It. and Sp. rubrica; from L. rubeo, to be red.]

1. In the canon law, a title or article in certain ancient law books; so called because written in red letters. Encyc.
2. Directions printed in prayer-books. The rubric and the rules relating to the liturgy are established by royal authority, as well as the liturgy itself. Nelson.