/frus"teuhm/ , n. , pl. frustums, frusta /-teuh/ . Geom.
1. the part of a conical solid left after cutting off a top portion with a plane parallel to the base.
2. the part of a solid, as a cone or pyramid, between two usually parallel cutting planes.
[ 1650-60; brúid (he) breaks, OE brysan to crush ]