Zorb n (Extreme Sports) a large air-cushioned hollow ball in which a person may ride, eg down a hill [C20 z + orb (sphere) + -ing1]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014