Circulation \Cir`cu*la"tion\, n. [L. circulatio: cf. F. circulation.]

1. The act of moving in a circle, or in a course which brings the moving body to the place where its motion began.

This continual circulation of human things. --Swift.

2. The act of passing from place to place or person to person; free diffusion; transmission.

The true doctrines of astronomy appear to have had some popular circulation. --Whewell.

3. Currency; circulating coin; notes, bills, etc., current for coin.

4. The extent to which anything circulates or is circulated; the measure of diffusion; as, the circulation of a newspaper.

5. (Physiol.) 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.

Source: Webster's Revised Unabridged Dictionary (1913)