noun

• 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 coins; notes, bills, etc., current for coin.
• The extent to which anything circulates or is circulated; the measurement of diffusion
• (strictly) The movement of the blood in the circulatory system, by which it is brought into close relations with the cells and tissues of the body; (loosely) the circulatory system.
• The movement of the sap in the vessels and tissues of plants.