Frustum

noun

noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    A cone or pyramid whose tip has been truncated by a plane parallel to its base.

    "In a parabolic conoid this difference vaniſhes, the fruſtum being always equal to a cylinder of the ſame height upon the ſection of the conoid that biſects the altitude of the fruſtum and is parallel to its baſes."

  2. 2
    a truncated cone or pyramid; the part that is left when a cone or pyramid is cut by a plane parallel to the base and the apical part is removed wordnet
  3. 3
    A portion of a sphere, or in general any solid, delimited by two parallel planes.

    "In some women it^([the os uteri]) is flat, in many more tuberose, and forming, as it were, a frustum of a sphere;[…]."

Example

More examples

"In a parabolic conoid this difference vaniſhes, the fruſtum being always equal to a cylinder of the ſame height upon the ſection of the conoid that biſects the altitude of the fruſtum and is parallel to its baſes."

Etymology

Borrowed from Latin frustum (“morsel”).

Related phrases

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.