Octohedra

Part of speech: noun

Definitions

1. A polyhedron characterized by eight faces, each of which is typically a triangle or quadrilateral
2. A geometric solid with eight flat surfaces, often used in mathematical and scientific contexts
3. An eight-faced three-dimensional figure, notable in both geometry and various applications in modeling and design

Etymology: "Octohedra" is the plural of "octohedron," so its history is that of the singular form. The singular is built from Greek roots: "okto," meaning eight, and "hedra," meaning seat or base, which in geometry came to mean a face of a solid. Together they describe a solid with eight faces. The plural follows the Latin-style pattern of changing the ending to "-a," which is why it appears in technical and mathematical writing rather than in everyday speech. Because the word is a formal coinage built from classical parts, it belongs to the body of geometric vocabulary that writers drew on when naming polyhedra. Its meaning is fixed by the component roots, so the plural simply refers to more than one such solid.