Synaxarion or Synexarion (plurals Synaxaria, Synexaria; Greek: Συναξάριον, from συνάγειν, synagein, "to bring together"; cf. etymology of synaxis and synagogue; Latin: Synaxarium, Synexarium; Coptic: ⲥϫⲛⲁⲝⲁⲣⲓⲟⲛ) is the name given in the Eastern Orthodox, Oriental Orthodox and Eastern Catholic Churches to a compilation of hagiographies corresponding roughly to the martyrology of the Roman Church.
There are two kinds of synaxaria:
The exact meaning of the name has changed at various times. Its first use was for the index to the Biblical and other lessons to be read in church. In this sense it corresponds to the Latin Capitulare and Comes. Then the Synaxarion was filled up with the whole text of the pericopes to be read. As far as the Holy Liturgy was concerned this meant that it was essentially transformed into the "Gospel" and "Apostle" books. Synaxarion remained the title for the index to the other lessons. Without changing its name it was filled up with complete texts of these lessons. The mere index of such lessons is generally called menologion heortastikon, a book now hardly needed or used, since the Typikon supplies the same, as well as other, information.
Certain calendars extant in the Middle Ages were also called Synaxaria. Krumbacher describes those composed by Christopher of Mytilene and Theodore Prodromus (twelfth century).