bipyramid
/ˌbaɪˈpɪrəmɪd/
noun
- A geometric solid formed by two pyramids joined at their bases, often having a symmetrical shape.
- In geometry class, we built a model of a bipyramid using straws and connectors.
- A diamond crystal can form a natural bipyramid shape.
- The mineral specimen had a perfect bipyramid structure with eight faces.