<p><strong>Noun:</strong></p><ul><li>A title, heading, direction, or the like, in a manuscript, book, statute, etc., written or printed in red or otherwise distinguished from the rest of the text.</li><li>A direction for the conduct of divine service or the administration of the sacraments, inserted in liturgical books.</li><li>Any established mode of conduct or procedure; protocol.</li><li>An explanatory comment; gloss.</li><li>A class or category (archaic).</li><li>Red ocher.</li></ul><p><strong>Adjective:</strong></p><ul><li>Written, inscribed in, or marked with or as with red; rubrical.</li><li>(Archaic) red; ruddy.</li></ul>