- noun any of various mechanical devices designed to propel the ball towards the wicket in order to provide batting practice. Early examples of the species are the Catapulta and the Balista, which were invented in the mid-19th century. But these Heath-Robinson contraptions were probably in their day a less cost-effective expedient than simply hiring the services of a professional bowler. Their modern descendants, however, make much better economic sense. One of the best-known contemporary bowling machines is Merlyn, now established as an indispensable member of many national sides.