- the insoluble protein end product of blood coagulation, formed from fibrinogen by the action of thrombin in the presence of calcium ions.
- Botany. a fibrinlike substance found in some plants; gluten.
- a white insoluble elastic protein formed from fibrinogen when blood clots: forms a network that traps red cells and platelets
- An elastic, insoluble, whitish protein derived from fibrinogen by the action of thrombin and forming an interlacing fibrous network in the coagulation of blood.
- A fibrous protein produced by the action of thrombin on fibrinogen and essential to the coagulation of blood. Fibrin works by forming a fibrous network in which blood cells become trapped, thereby producing a clot.