n-disc <topology, geometry>
geometry isomorphic to the set of points X in 𝔼n such that ‖X‖≤1 set of all points in 𝔼n less than or equal to one-unit distance from the origin
Note to entry: The 0-disc is a point. The 1-disc is a line. The 2-disc is a circle and its interior. The 3-disc is a sphere and its interior (a ball).
ORIGIN: ISO/TC 211 Glossary of Terms - English (last updated: 2020-06-02)