inside; within; inner; internal; specifically refers to the interior or domestic domain as opposed to the exterior or foreign domain; often used in spatial or temporal contexts

(sports) to cut in (basketball); to slice or chop the ball (tennis, table tennis)

ball-shaped object; ball used in sports

(mathematics) to inscribe or be internally tangent to a geometric figure

(math) solid geometric figure where every point on the surface is equidistant from the center