Nouns

(n)surgerythe branch of medical science that treats disease or injury by operative procedures“he is professor of surgery at the Harvard Medical School”
(n)surgerya room where a doctor or dentist can be consulted“he read the warning in the doctor's surgery”
(n)operating room, OR, operating theater, operating theatre, surgerya room in a hospital equipped for the performance of surgical operations“great care is taken to keep the operating rooms aseptic”
(n)operation, surgery, surgical operation, surgical procedure, surgical processa medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body“they will schedule the operation as soon as an operating room is available”, “he died while undergoing surgery”