Definition of "operating theater" []

• A room in a hospital equipped for the performance of surgical operations (noun)

WordNet. Princeton University. 2010.

• "The man on the table ceased to be Jorgenson, the excessively gadgety Infirmary became again the main operating theater of that same Mayo's which had produced Brown and this strange new machine, and his fingers were again those of the Great Ferrel, the miracle boy from Mayo's, who could do the impossible twice before breakfast without turn­ing a hair."