Definition of circulation

The word "circulation" has its roots in the 14th century Latin word "circulatio," meaning "a turning or revolving around." This Latin term was derived from "circulus," meaning "circle" or "ring," and "are," a suffix indicating agency or action. The Latin "circulatio" was used in various contexts, including medicine, to describe the flow or movement of body fluids, such as blood or bile. In the 16th century, the term "circulation" was borrowed into Middle English, retaining its original meaning of "the act of circulating or moving in a circular motion." Over time, the medical application of "circulation" became more specific, referring to the movement of blood through the body's vessels, a concept first described by English physician William Harvey in the 17th century. Since then, the term has expanded to encompass other forms of circulation, such as money, air, or information.