: a white insoluble fibrous protein formed from fibrinogen by the action of thrombin especially in the clotting of blood
Examples of fibrin in a Sentence
Recent Examples on the Web
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
When mixed, the two form a fibrin network, mimicking the body's natural healing process.
—
Lucy Notarantonio,
MSNBC Newsweek,
18 June 2025
Whichever the case, the fibrin often gets inadvertently broken up in the process, with some of the pieces proceeding to travel down the blood vessel.
—
Ben Coxworth,
New Atlas,
7 June 2025
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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
When mixed, the two form a fibrin network, mimicking the body's natural healing process.
—
Lucy Notarantonio,
MSNBC Newsweek,
18 June 2025
Whichever the case, the fibrin often gets inadvertently broken up in the process, with some of the pieces proceeding to travel down the blood vessel.
—
Ben Coxworth,
New Atlas,
7 June 2025
Cite this Entry
“Fibrin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fibrin. Accessed 2 Jul. 2026.
Copy CitationKids 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
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