noun
or heir·mos irˈmȯs
( plural hir·moi or heir·moi -ˈmē)
Etymology: Late Greek heirmos, from Greek, series, sequence, connection; akin to Greek lirein to fasten together — more at series
: a troparion, hymn, or canticle with a fixed rhythm and melody that is used as a standard rhythmic and melodic pattern for other troparia in the canon of the Eastern Church