A very educated and talented person in the field of emergency medicine.

Someone who is quick, sufficient, and very well versed in every aspect of the emergency room.

A person that works in the ER that has mastered everything and is therefore a ninja in the ER.
Preston really knows his stuff, he is quintessentially an ER Ninja.

Did you see that ER Ninja? He was so fast in taking care of that difficult situation he practically made it disappear.
by Night.ER.Ninja July 27, 2014
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