Wiktionary
n. A physician (or doctor) who works at an emergency department to care for acutely ill patients.
Wikipedia
An emergency physician is a physician who works at an emergency department to care for acutely ill patients. The emergency physician is a specialist in advanced cardiac life support ( advanced life support in Europe), trauma care such as fractures and soft tissue injuries, and management of other life-threatening situations.
In some European countries (e.g. Germany, Belgium, Poland, Austria and Denmark), emergency physicians/anaesthetists are also part of the emergency medical service and are dispatched together with EMTs and paramedics in cases of potentially life-threatening situations for patients (heart attacks, serious accidents, resuscitations or unconsciousness, strokes, drug overdoses, etc.). In the United States, emergency physicians are mostly hospital-based, but they often work on air ambulances and mobile intensive-care units.
When a patient is brought into the emergency department, he or she is usually sent to triage first. The patient may be triaged by an emergency physician, a paramedic, or a nurse; in the United States, triage is usually performed by a registered nurse. If the patient is admitted to the hospital, another physician such as a cardiologist or neurologist takes over from the emergency physician.