Definition of ball-up:
(n) :
A solid or hollow sphere, or roughly spherical mass.
(n) :
A quantity of string, thread, etc., wound into a spherical shape.
(n) :
(mathematics) Homologue or analogue of a disk in the Euclidean plane.
(n) :
(mathematics) In 3-dimensional Euclidean space, the volume bounded by a sphere.
(n) :
(mathematics) The set of points in a metric space of any number of dimensions lying within a given distance (the radius) of a given point.
(n) :
(mathematics) The set of points in a topological space lying within some open set containing a given point.