: 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
How the tool works Traditional methods of monitoring platelet activity often rely on indirect measurements or invasive procedures.
—
Reem Amro, FOXNews.com, 18 May 2025
The pope was also diagnosed with thrombocytopenia, a condition characterized by a low count of the platelets in blood that help to form clots.
—Willem Marx, NPR, 25 Feb. 2025
But the new finding published in the journal Blood shows that these stem cells, capable of producing a variety of cells including red blood cells and platelets which form blood clots and aid in tissue healing, are also found in the lungs.
—Victoria Forster, Forbes, 15 Mar. 2025
Injuries, straining, low platelets (cells that form a plug to stop the bleeding after injury), platelet dysfunction, and weak or swollen blood vessels can also cause petechiae.23
Certain health conditions and medications can cause petechiae.
—Brandi Jones, Msn-Ed, Health, 7 Feb. 2025
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Reem Amro, FOXNews.com, 18 May 2025
The pope was also diagnosed with thrombocytopenia, a condition characterized by a low count of the platelets in blood that help to form clots.
—Willem Marx, NPR, 25 Feb. 2025
But the new finding published in the journal Blood shows that these stem cells, capable of producing a variety of cells including red blood cells and platelets which form blood clots and aid in tissue healing, are also found in the lungs.
—Victoria Forster, Forbes, 15 Mar. 2025
Injuries, straining, low platelets (cells that form a plug to stop the bleeding after injury), platelet dysfunction, and weak or swollen blood vessels can also cause petechiae.23
Certain health conditions and medications can cause petechiae.
—Brandi Jones, Msn-Ed, Health, 7 Feb. 2025
See All Example Sentences for platelet
Cite this Entry
“Platelet.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/platelet. Accessed 8 Jun. 2025.
Copy CitationKids Definition
platelet
noun
plate·let
ˈplāt-lət 
: one of the tiny colorless disk-shaped bodies of the blood of mammals that assist in blood clotting
Medical Definition
platelet
noun
plate·let
ˈplāt-lət
: 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
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