Possible Definitions:
1. Hexagram (n.) A figure of six lines
2. Hexagram (n.) A figure composed of two equal triangles intersecting so that each side of one triangle is parallel to a side of the other, and the six points coincide with those of a hexagon.
3. Hexagram (n.) In Chinese literature, one of the sixty-four figures formed of six parallel lines (continuous or broken), forming the basis of the Yih King, or "Book of Changes."