Agnus Dei

plural Agnus Deis

1. ChristianityA liturgical chant recited as part of the Mass, beginning with those words, or the music to which it is set.First known use 10th c.
2. CatholicismA small model, picture, or heraldic representation of a lamb with a cross and sometimes a flag (usually white with a red cross).
3. CatholicismA bar of wax imprinted with a similar shape and blessed by the Pope.First known use 16th c.

   The most common of these amulets was the agnus dei, a small wax cake, originally made out of paschal candles and blessed by the Pope, bearing the image of the lamb and flag.

   1971, Keith Thomas, Religion and the Decline of Magic, Folio Society, published 2012, page 28

   1 more example

   Matilda continued her incantations; at intervals she took various items from the basket, the nature and name of most of which were unknown to the friar: but among the few which he distinguished, he particularly observed three human fingers, and an agnus dei, which she broke in pieces.

   1796, Matthew Lewis, The Monk, Folio Society, published 1985, page 194