Co*ag`u*la"tion (?), n. [L. coagulatio.] 1. The change from a liquid to a thickened, curdlike, insoluble state, not by evaporation, but by some kind of chemical reaction; as, the spontaneous coagulation of freshly drawn blood; the coagulation of milk by rennet, or acid, and the coagulation of egg albumin by heat. Coagulation is generally the change of an albuminous body into an insoluble modification.

2. The substance or body formed by coagulation.

• the process by which blood forms solid clots
  
• similar solidification of other materials (e.g. tofu).