Wiktionary
n. 1 (l en fraternisation Fraternisation) between (l en men). 2 (context history religion English) (l en ceremony Ceremony) where males are (l en unionised) with one‐another.
Wikipedia
Adelphopoiesis, or adelphopoiia from the Greek , derived from (adelphos) "brother" and (poieō) "I make", literally "brother-making" is a ceremony practiced historically in some Christian traditions to unite together two people of the same sex (normally men) in church-recognized friendship.
Similar blood brotherhood rituals were practiced by other cultures, including American Indians, ancient Chinese as well as Germanic and Scandinavian peoples.
Such ceremonies can be found in the history of the Catholic Church until the 14th century and in the Eastern Orthodox Church until the 18th century. Documented in Byzantine manuscripts from the ninth to the fifteenth centuries, prayers established participants as "'spiritual brothers' (pneumatikous adelphous) and contained references to sainted pairs, including most notably SS Sergius and Bacchus, who were famous for their friendship."
In the late twentieth century, the defunct Christian tradition gained notoriety as the focus of controversy involving advocates and opponents of secular and religious legalization of homosexual relationships in the West.