Wikipedia
Kourbania
Kourbania (; via Turkish Kurban; from the Arabic qurban "sacrificial victim"; compare Hebrew korban) refers to a practice of Christianized animal sacrifices in some parts of Greece. It usually involves the slaughter of lambs as "kourbania" offerings to certain saints.
In antiquity the sacrifice was offered for health (or following an accident or illness), as a votive offering promised to the Lord by the community, or by the relatives of the victim. Writing in 1979, Stella Georgoudi stated that the custom survived in "some villages of modern Greece" and was "slowly deteriorating and dying out".
A similar custom from Bulgaria known as Kurban is celebrated on St. George's day.