a round building without a roof and with rows of seats that rise in steps around an open space. Amphitheatres were used especially in ancient Greece and Rome for public entertainments. （尤指古希腊和古罗马的）圆形露天剧场，圆形露天竞技场 
The Roman amphitheatre stands just outside the fortress walls. 古罗马竞技场就坐落在城墙外。
a room, hall or theatre with rows of seats that rise in steps 阶梯式座位大厅（或剧场、室） - (specialist)
an open space that is surrounded by high sloping land 圆形凹地 The path emerges from the gorge into an open amphitheatre with slopes all around. 这条小路从峡谷延伸到一个开阔的圆形剧场，四周都是斜坡。
Word Originlate Middle English: via Latin from Greek amphitheatron, from amphi ‘on both sides’ + theatron, from theasthai ‘behold’.