The Polychronion (Greek: Πολυχρόνιον, `many years` or `long-lived`, literally `long-timed`; მრავალჟამიერი, mravaljamieri; мъногаꙗ лѣта mŭnogaja lěta) is a solemn encomium chanted in the liturgy of the Eastern Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite...
a prayer for the long life of a person or persons, sung mostly on festive occasions