platelet

American  

[pleyt-lit] / ˈpleɪt lɪt /

noun

Cell Biology.

1. a small platelike body, especially a blood platelet.

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platelet British  

/ ˈpleɪtlɪt /

noun

1. Formerly called: thrombocyte.  a minute cell occurring in the blood of vertebrates and involved in clotting of the blood

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platelet Scientific  

/ plāt′lĭt /

1. Any of the numerous small, round cell fragments found in the blood of mammals that function in the clotting of blood. Platelets contain no nuclei and are formed in the bone marrow from precursor cells called megakaryocytes. Platelets contribute to the coagulation process by adhering to damaged blood vessels, fibrinogen, and other platelets. An inadequate number of platelets leads to uncontrolled bleeding.

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Etymology

Origin of platelet

First recorded in 1890–95; plate ¹ + -let

Explanation

Platelets are tiny cell fragments that help your blood to clot. If you cut yourself, platelets clump together to slow the flow of blood and plug the cut. Blood clots are your body's way of repairing and healing cuts and scrapes in your skin, and platelets are an essential part of the clotting process. They're colorless disks, pieces of cells with no nuclei, and they're formed in your bone marrow along with white and red blood cells. Doctors and scientists measure blood in microliters, tiny drops, and a healthy person has as many as 450,000 platelets in one microliter of blood.

Example Sentences

Inflammatory indicators included C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and platelet count.

From Science Daily • Apr. 13, 2026

Low-dose naltrexone has been shown to reduce fatigue and lower platelet aggregation.

From Science Daily • Jan. 8, 2026

There are modest risks for taking antidepressants over a lifetime, says Lenze, such as bleeding because some inhibit platelet function.

From The Wall Street Journal • Nov. 11, 2025

On Sunday, the Pope's thrombocytopenia - a condition that occurs when the platelet count in the blood is too low - was stable, the statement said.

From BBC • Feb. 23, 2025

Bull had started down the slope now, his boards out, and he was descending, alive, alive, adrenaline reinforcing every platelet, every blood cell, and his mind radiating with its response to danger.

From "The Great Santini" by Pat Conroy