theater

noun

1. (US, countable)A place or building, consisting of a stage and seating, in which an audience gathers to watch plays, musical performances, public ceremonies, and so on.
2. (US, countable, uncountable)A region where a particular action takes place; a specific field of action, usually with reference to war.

   “His grandfather was in the Pacific theater during the war.”

   “Percy had been too big for the town since he got back from the war. He served in the Pacific theater, behind the lines keeping up the supply chain.”

3. (US, countable, uncountable)A lecture theatre.
4. (US, countable, uncountable)An operating theatre or locale for human experimentation.

   “This man is about to die, get him into theater at once!”

5. (US, countable, uncountable)A cinema.

   “We sat in the back row of the theater and threw popcorn at the screen.”

6. (US, countable, uncountable)Drama or performance as a profession or art form.

   “I worked in theater for twenty-five years.”

7. (US, countable, uncountable)Any place rising by steps like the seats of a theater.
8. (US, countable, derogatory, figuratively, uncountable)A conspicuous but unproductive display of action.

   “The Senate confirmation hearings were just theater.”

   “security theater; hygiene theater”

   “ACTA proponents rely on claims of a growing piracy and counterfeiting threat. In the absence of credible evidence of the threat or that the measures in ACTA will reduce the threat, ACTA is no more than enforcement theater.”