theater是美式拼法,意思是剧院;剧场;戏剧;战场;(某一国,某一作家的)戏剧作品;例如:Theater owners lease films from film distributors.
theatre是英式拼法,意思是剧场;剧院;戏剧;露天剧场;戏剧工作;演出;上演;战场。例如:The article is very good PR for the theatre.