An oval or circular building with rising tiers of seats about an open space called the arena
Anything resembling an amphitheater in form; as, a level surrounded by rising slopes or hills, or a rising gallery in a theater
am·phi·thea·tre amphitheatres in AM, use amphitheater An amphitheatre is a large open area surrounded by rows of seats sloping upwards. Amphitheatres were built mainly in Greek and Roman times for the performance of plays. a large circular building without a roof and with many rows of seats (amphitheatrum, from , from amphi- ( AMPHIBIOUS) + theatron ( THEATER))