in the Eastern Orthodox church, a part of the Eucharistic liturgy in which the deacon pours a few drops of hot water (known as the zeon, or living water) into the chalice. The origin of the rite is not known, though it is clearly very ancient. It is explained as symbolizing the fervour (i.e., heat) of faith or the descent of the Holy Spirit.
ZEON
Meaning of ZEON in English
Britannica English vocabulary. Английский словарь Британика. 2012