Spring ball

grabcad

People generally associate the term "spring" with a type of coiled metal object known as a coil spring. The phrase could refer to other uses, such as types of shoes (ball shoe), people or items that move around (spry type person), a slang name for someone that gets their hands on something by force (jack the spring type person), etc., and could refer specifically to something used with or similar in appearance to "ball" sporting goods, perhaps being related in use or action.