fibrin

noun

fi·​brin ˈfī-brən 

: a white insoluble fibrous protein formed from fibrinogen by the action of thrombin especially in the clotting of blood

fibrinous

ˈfī-brə-nəs 

adjective

Examples of fibrin in a Sentence

Recent Examples on the Web

In the team’s earlier design, the very soft fibrin gel tended to wrinkle as the muscle cells pulled against it. — New Atlas, 3 Oct. 2026

Experimental studies have shown that MASP-2 can amplify thromboinflammation, promote thrombin generation, and contribute to fibrin formation. — Steve Brozak, Forbes.com, 15 May 2026

Let’s take a closer look at the options—fibrin glue and the surgical net. — Jolene Edgar, Allure, 16 Mar. 2026

The clot, or thrombus, is made of fibrin, platelets, white blood cells and some red blood cells. — Daryl Austin, USA Today, 15 Aug. 2025

Word History

First Known Use

1800, in the meaning defined above

Kids Definition

fibrin

noun

fi·​brin ˈfī-brən 

: a white fibrous substance that is difficult to dissolve and is formed in the clotting of the blood

Medical Definition

fibrin

noun

fi·​brin ˈfī-brən 

: a white insoluble fibrous protein formed from fibrinogen by the action of thrombin especially in the clotting of blood