noun Crystallography.

a form symmetrical about a plane dividing it into two pyramids.

Origin of bipyramid

Also called dipyramid.
Related formsbi·py·ram·i·dal [bahy-pi-ram-i-dl] /ˌbaɪ pɪˈræm ɪ dl/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for bipyramid



a geometrical form consisting of two pyramids with a common polygonal base
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012