free movement or passage (as of cytoplasm within a cell or sap through a plant); "ocean circulation is an important part of global climate"; "a fan aids air circulation"
(特に、細胞の中の細胞質、または、植物の中を通る樹液のような)自由な動きまたは移動
circulation
the spread or transmission of something (as news or money) to a wider group or area