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Noun. 1. blood coagulation-a process in which liquid blood is changed into a semisolid mass (a blood clot). blood clotting. clotting, coagulation, curdling-the process of forming semisolid lumps in a liquid.1  Facebook.oun. 1. blood coagulation-a process in which liquid blood is changed into a semisolid mass (a blood clot). blood clotting. clotting, coagulation, curdling-the process of forming semisolid lumps in a liquid.
Freebase(0.00 / 0 votes)Rate this definition: Downregulation and upregulation. Downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external variable. An increase of a cellular component is called upregulation.