Hirmologium (εἱρμολόγιον), an office-book in the Greek Church, consisting mainly of a collection of the Hirmoi, but containing also a few other forms. Hirmus (εἱρμός). The Canons, which form so important a part of the Greek offices, are divided into nine odes, or practically into eight, as the second is always omitted. Each ode consists of a varying number (three, four, or five are the numbers most frequently found) of troparia, or short rhythmical strophes, each formed on the model of one which precedes the ode, and which is called the Hirmus. The Hirmus is usually independent of the ode, though containing a reference to the subject matter of it; sometimes, however, the first tiroparion of an ode is called the Hirmus. It is distinguished by inverted commas (' ") in the office-books. Sometimes the first words alone-of a Hirmus are given, and it is not unfrequently placed at the end of the ode to which it belongs.