Capittum (or Capitular) is
(1) Properly a summary or heading, under which many particulars are arranged.
(2) Hence, in the plural, codes of law, ecclesiastical or civil, digested under chapters or capita.
(3) The word came also to mean the "chapter" itself, of which it is properly the heading; as, e.g. the capitula or short lessons for particular days.
(4) From this last-mentioned usage, coupled with the practice of reading a capifulum, or chapter of the rule or of the Scriptures, to the assembled canons or monks, these came to be called, in a body, the capitulum, or chapter.
(5) The "little chapter" said at all the canonical hours excepting matins, after the Psalms. It consists of one or two verses of Scripture, usually taken from the Epistles, often from the Prophets, and occasionally from other parts; and is recited by the officiating priest, standing.
(6) An anthem in the Ambrosian rite said at lauds after the Psalms and before the antiphon, varying with the day.