From The Collaborative International Dictionary of English v.0.48:
Paten \Pat"en\, n. [LL. patina, patena, fr. L. patina, patena, a
pan; cf. L. patere to be open, E. patent, and Gr. pata`nh a
kind of flat dish: cf. F. pat[`e]ne. Cf. Patina.]
1. A plate. [Obs.]
[1913 Webster]
2. (Eccl.) The place on which the consecrated bread is placed
in the Eucharist, or on which the host is placed during
the Mass. It is usually small, and formed as to fit the
chalice, or cup, as a cover.
[1913 Webster] [Written also patin, patine.]
[1913 Webster]