Sphragis

Sphragis (Σφραγίς, seal,) a name given in the ancient Church to baptism. Being rather uncommon as applied to baptism, it has occasioned some error among learned men, who often mistake it either for the sign of the cross, or the consignation, and the unction that was used in confirmation. The imposition of hands in ordination was called σφραγίς (consignation) and σταυροειδὴς σφραγίς (consignation in form of a cross), because the sign of the cross was made on the head of him that was ordained. See Bingham, Christ. Antiq. bk. 4, ch. 6, § 12; bk. 12, ch. 1, § 4.