theatre-in-the-round n, pl theatres-in-the-round1. (Theatre) a theatre with seats arranged around a central acting area2. (Theatre) drama written or designed for performance in such a theatre Also called: arena theatreCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014