1 [noncount] a : the movement of blood through the body that is caused by the pumping action of the heart
▪ He has bad circulation in his legs. ▪ The drug improves blood circulation.
b : movement of air, water, etc., through the different parts of something
▪ The attic has poor air circulation. ▪ the circulation of ocean waters ▪ Let's open the windows to get some circulation in here. 2 [noncount] : the act of passing something (such as money, information, etc.) from person to person or place to place
▪ This memo is not meant for circulation. : the state of being passed from person to person or place to place ▪ The coins have recently entered circulation. ▪ That rumor has been in circulation [=has been going around] for a long time. ▪ The magazine has been taken out of circulation. [=the magazine will no longer be made and sold] 3 [noncount] : the state of being actively involved in social activities (such as parties or dates)
▪ She's finally getting back in/into circulation after her divorce. [=she has started dating and going out again after her divorce] ▪ He'll be out of circulation [=unable to go out socially] for a while after the surgery. 4 [count] : the average number of copies of a newspaper, magazine, etc., that are sold over a particular period
▪ The newspaper has the largest circulation in the country. ▪ The magazine has a weekly circulation of about 70,000 subscribers nationwide.