1.  Derived from a Latin word meaning a small image or symbol engraved in wax, it means a symbol or “signature” of a spirit or non-material entity.  It is used either in evoking the spirit for communication, invoking the entity for inspiration, or using the power of the being in talismans, amulets, etc.

2.  A term from the 13^th century meaning to close up (as in "seal an envelope") using wax, cement, lead, etc. Magickally, it refers to closing something off, as in sealing an unwanted spirit in its own plane or sealing unwanted energy out of a magickal circle.