- 1[uncountable] the movement of blood around the body Regular exercise will improve blood circulation. to have good/bad circulation
- 2[uncountable] the passing or spreading of something from one person or place to another the circulation of money/information/ideas A number of forged tickets are in circulation. The coins were taken out of circulation. Copies of the magazine were withdrawn from circulation. putting computer viruses into circulation
- 3[uncountable] the fact that someone takes part in social activities at a particular time Anne has been sick but now she's back in circulation. I was out of circulation for months after the baby was born.
- 4[countable, usually singular] the usual number of copies of a newspaper or magazine that are sold each day, week, etc. a daily circulation of more than one million
- 5[uncountable, countable] the movement of something (for example air, water, gas, etc.) around an area or inside a system or machine Poor air circulation can cause condensation.