1 [ uncountable ] the movement of blood around the body

2 [ uncountable ] the passing or spreading of sth from one person or place to another

3 [ uncountable ] the fact that sb takes part in social activities at a particular time

4 [ countable , usually singular ] the usual number of copies of a newspaper or magazine that are sold each day, week, etc

5 [ uncountable ,  countable ] the movement of sth (for example air, water, gas, etc.) around an area or inside a system or machine