pyramoidGeom.rare—0.|ˈpɪrəmɔɪd| [ad.Gr. πῡραµοειδής pyramid-shaped, f. πῡραµίς pyramid: see -oid.] = pyramidoid (Webster 1864). So pyraˈmoidala.= pyramidoidal b. 1883Heddle in Encycl.Brit. XVI. 354/2 Producing..in the hexagonal system ‘pyramoidal’ and ‘gyroidal’ forms.