noun Geometry.

a solid having sides that are trapezoids and bases or ends that are parallel and similar but not congruent polygons.Compare prism(def 2).

Origin of prismoid

First recorded in 1695–1705; prism + -oid
Related formspris·moi·dal, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for prismoid



a prismatoid having an equal number of vertices in each of the two parallel planes and whose sides are trapeziums or parallelograms
Derived Formsprismoidal, adjective

Word Origin for prismoid

C18: from French prismoïde; see prism, -oid
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