the act of moving in a circle, or in a course which brings the moving body to the place where its motion began.-the act of passing from place to place or person to person; free diffusion; transmission.-currency; circulating coin; notes, bills, etc., current for coin.-the extent to which anything circulates or is circulated; the measure of diffusion; as, the circulation of a newspaper.-the movement of the blood in the blood-vascular system, by which it is brought into close relations with almost every living elementary constituent. also, the movement of the sap in the vessels and tissues of plants.