rhombohedron

noun, plural rhom·bo·he·drons, rhom·bo·he·dra [rom-buh–hee-druh] /ˌrɒm bəˈhi drə/.

1. a solid bounded by six rhombic planes.

noun

1. a six-sided prism whose sides are parallelograms

Plural rhombohedrons rhombohedra

1. A prism with six faces, each a rhombus.