Lewis & Short

sphrāgis, īdis, f., = σφραγίς (a seal).

  1. I. A kind of stone used for seals, Plin. 37, 8, 37, § 117.
  2. II. Another name for Lemnian earth, so called because sold in sealed packets, Plin. 35, 6, 14, § 33.
  3. III. A little ball of plaster in medicine, Cels. 5, 26, 23 (5, 20, 2, written as Greek).