Phylactery (Gr. , from , to guard), a name given to any amulet or charm worn by the ancients to guard them against danger and disease, or, as among the Hebrews, against transgression. Among the latter it was a strip of parchment, upon which were written passages from the Scriptures, and which, folded up and placed in a small leather box, was worn by the devout principally on the forehead. Among orthodox modern Jews, they are attached to the head and to the left arm, but worn only during morning prayers, and only on work days. They are known as tephillah (from tephillah, prayer), and as such distinguished from similar marks of warning attached to the door posts, and from the latter called rnezuzoth. Very fine vellum is employed, and the writing traced with great care, while the case in which they are enclosed is made of several layers of parchment or of black calfskin. - Among the early Christians, a phylactery was often used as an amulet, a practice forbidden by the council of Laodicea.