Genuflection (or genuflexion), bending at least one knee to the ground, a gesture of deep respect for a superior. Lay people or clergy of lesser rank genuflect to a prelate and kiss his episcopal ring, as a sign of acceptance of the bishop’s apostolic authority as representing Christ in the local church.
Genuflecting before the bishop of the diocese to which one belongs was treated as obligatory in editions of the Caeremoniale Episcoporum earlier than that of 1985.
In the same period, the clergy genuflected when passing before the bishop of the diocese when he presides at a liturgical ceremony. But the officiating priest, as also all prelates, canons, etc., were dispensed, and substituted a bow of the head and shoulders for the genuflection.
Genuflection to the Blessed Sacrament, especially when arriving or leaving its presence, is a practice in the Anglican Communion, the Latin Rite Catholic Church, and the Lutheran Church.
(Wikipedia)