plate·​let | \ˈplāt-lət \

Definition of platelet 

: a minute flattened body (as of ice or a mineral) especially : a minute colorless disklike body of mammalian blood that assists in blood clotting by adhering to other platelets and to damaged epithelium

called also blood platelet, thrombocyte

Examples of platelet in a Sentence

Recent Examples on the Web

A few hours after the shooting, the Gulf Coast Regional Blood Center posted on Facebook that area facilities were requesting more platelets and O-negative red cells. Emilie Ikeda, Fox News, "Texas blood center opens extra locations amid high demand to give blood," 19 May 2018 The results showed that Tazmin had a low-platelet disorder. Lindsey Bever, Washington Post, "A mother Googled her toddler’s symptoms — and believes it may have saved the child’s life," 24 Feb. 2018 Platelet BioGenesis, which was founded in 2014, said Wednesday that the grant will help the startup develop a bioreactor that is key to the production of platelets, a critical component of blood that promotes clotting. Jonathan Saltzman — Boston Globe, STAT, "Department of Defense funds biotech making blood platelets from stem cells," 28 June 2018 By then my platelets had finally stabilized at a level high enough to rule out spontaneous bleeding. Kyle Dickman, Outside Online, "A Rattle with Death in Yosemite," 20 June 2018 Importantly, Mendell said the patients treated so far are showing no signs of adverse immune reactions, no kidney issues, and no drops in red blood cells or platelet counts. Adam Feuerstein, STAT, "With tantalizing early results, Sarepta’s gene therapy for Duchenne raises hopes for ‘real change’," 19 June 2018 Meanwhile another venom protein, disintegrin, acted as a magnet to my platelets and fibrinogen, molecular components that help blood clot. Kyle Dickman, Outside Online, "A Rattle with Death in Yosemite," 20 June 2018 Each platelet is only a few millionths of a metre across. The Economist, "Making buildings, cars and planes from materials based on plant fibres," 14 June 2018 The bioreactor would mimic the environment inside bone marrow, the sponge-like tissue that produces platelets. Jonathan Saltzman,, "Department of Defense gives $3.5m to biotech making blood platelets from stem cells," 27 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'platelet.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of platelet

1888, in the meaning defined above

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Last Updated

4 Oct 2018

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The first known use of platelet was in 1888

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More Definitions for platelet



English Language Learners Definition of platelet

: a small, round, thin blood cell that helps blood to stop flowing from a cut by becoming thick and sticky


plate·​let | \ˈplāt-lət \

Kids Definition of platelet

: one of the tiny colorless disk-shaped bodies of the blood that assist in blood clotting


plate·​let | \ˈplāt-lət \

Medical Definition of platelet 

: a minute colorless anucleate disklike body of mammalian blood that is derived from fragments of megakaryocyte cytoplasm, that is released from the bone marrow into the blood, and that assists in blood clotting by adhering to other platelets and to damaged epithelium

called also blood platelet, thrombocyte

More from Merriam-Webster on platelet

Britannica English: Translation of platelet for Arabic Speakers Encyclopedia article about platelet

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