amphitheatre

n. stadium, arena (also amphitheater)

The name amphitheatre (alternatively amphitheater) refers to a level, open space surrounded by an oval area that gradually ascends. The area may be a man-made structure or a natural geographic formation, but it is suited for seating people on the sloping area for the viewing of spectator sports, games, concerts, displays, rallies, or theatrical performances. An amphitheatre can be classified as either an ancient amphitheatre, a contemporary amphitheatre, or a natural amphitheatre.
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Noun
1. a sloping gallery with seats for spectators (as in an operating room or theater)
(synonym) amphitheater
(hypernym) gallery
(part-meronym) tiered seats
(classification) dramaturgy, dramatic art, dramatics, theater, theatre
2. an oval large stadium with tiers of seats; an arena in which contests and spectacles are held
(synonym) amphitheater, coliseum
(hypernym) stadium, bowl, arena, sports stadium
(hyponym) Colosseum
(part-meronym) vomitory

n. stadium, amphitheater

(n.)
Anything resembling an amphitheater in form; as, a level surrounded by rising slopes or hills, or a rising gallery in a theater.
  

(n.)
An oval or circular building with rising tiers of seats about an open space called the arena.