Wikipedia
Endecha
The endecha is a subgenre of lament, planto, found in early Iberian music. It usually indicates a metrical composition of 4 verses with 6 or 7 syllables. The endecha is essentially a musical form; a hexasyllable.
The verb endechar - to lament, to sing endechas, is rarely encountered, though found in testimonies by Alfonso de Palencia. It comes from the time before the Expulsion of 1492, and was used within the Jewish community, though popular poems in Galicia already used this type of versification.