frustum
noun [ C ] uk/ˈfrʌs.təm/ us/ˈfrʌs.təm/ frusta /ˈfrʌs.tə/ /ˈfrʌs.tə/ frustums
mathematics specialized平截头体，截头锥体
the part of a solid shape such as a cone that is between the base of the shape and a parallel plane through the shape or between two parallel planes through the shape