pentacle

noun

1. A flat talisman, almost always disk-shaped, made of parchment, sheet metal, or other substance, marked with a magic symbol or symbols, used in magical evocation.
2. A pentagram, or a disk with a pentagram on it, especially one that is used for magical or mystical purposes.
3. A circumscribed pentagram.
4. A figure formed by two equilateral triangles intersecting regularly so as to form a six-pointed star.