What does coagulation mean?
Coagulation is the process by which a liquid changes into a thickened, semi-solid or solid state, most familiar as the clotting of blood. When a vessel is injured, a cascade of proteins in the plasma triggers the conversion of fibrinogen into fibrin, which weaves a mesh that traps cells and forms a clot, halting bleeding — a vital mechanism without which even minor wounds could be dangerous. The term also applies beyond physiology: in food science it describes milk curdling under rennet or egg proteins firming with heat, and in industry it covers similar thickening processes. Coagulation belongs chiefly to technical registers — medicine, biochemistry, cooking science — where it appears in phrases such as 'blood coagulation,' 'coagulation cascade,' and 'coagulation factors.' Its derivatives include the verb coagulate and the noun coagulant, denoting an agent that induces the process. Precise and descriptive, the word captures one of biology's most essential transformations.
nounThe process by which a liquid, especially blood, changes into a thickened, semi-solid or solid state; the action or result of clotting. In medicine and physiology it refers specifically to the transformation of blood from a fluid into a gel-like clot at the site of injury.
- The physiological process by which blood forms a clot to stop bleeding.
- The general thickening or curdling of any liquid into a semi-solid state (as with milk, egg proteins, or industrial fluids).
"Coagulation of the blood began almost immediately, sealing the wound and preventing further loss."
"Doctors ran tests on her coagulation before surgery to make sure her blood would clot normally."
"The addition of rennet triggered the coagulation of the milk, separating it into curds and whey."
Coagulation is normally used as an uncountable mass noun referring to the process; the plural form exists grammatically but is rare, appearing only when counting distinct instances of coagulation events.
"Multiple distinct coagulations were observed across the samples during the experiment."
Your blood contains a cascade of more than a dozen proteins poised to turn liquid into life-saving jelly within seconds — coagulation is why you don't bleed out from a paper cut.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of coagulation
Coagulation derives from the Latin verb coagulare, meaning 'to cause to clot' or 'to curdle', itself formed from cogere ('to drive together, compel'), composed of com- ('together') plus agere ('to drive, do'). The word entered English via Latin usage, becoming established in English scientific writing around the early 17th century as natural philosophers described the curdling of liquids and the clotting of blood. It shares this Latin root with related terms such as coagulate, coagulant, and coagulable, all built on the same stem.
Related word forms
How coagulation is actually used
Coagulation is primarily a scientific, medical, and technical register — common in medicine (haematology), food science, and chemistry. It carries a neutral, clinical connotation rather than an everyday one; in casual speech people are far more likely to say 'the milk curdled' than 'the milk underwent coagulation.' British spelling conventions apply in UK medical contexts.
Easily confused with coagulation
A coagulant is a substance that causes coagulation; coagulation is the process itself.
Consolidation means combining or strengthening into a single whole, whereas coagulation is the physical thickening or clotted setting of a liquid.