noun
rhombohedron
A solid figure bounded by six rhombic faces; a technical term in geometry and crystallography.
菱面体は、すべての面が合同な菱形である平行六面体です。
A rhombohedron is a parallelepiped whose faces are all congruent rhombuses.
Compound of 菱 (りょう, 'rhombus') + 面 (めん, 'face') + 体 (たい, 'body, solid'), literally 'rhombus-faced solid'.