cir·cu·la·tion 
(sûr′kyə-lāshən)
(sûr′kyə-lāshən)n.
1. Movement in a circle or circuit, especially the movement of blood through bodily vessels as a result of the heart's pumping action.
2.
a. Movement or passage through a system of vessels, as of water through pipes; flow.
b. Free movement or passage.
3. The passing of something, such as money or news, from place to place or person to person.
4.
a. The condition of being passed about and widely known; distribution.
b. Dissemination of printed material, especially copies of newspapers or magazines, among readers.
c. The number of copies of a publication sold or distributed.