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platelet

American  
[pleyt-lit] / ˈpleɪt lɪt /

noun

Cell Biology.
platelets plural
  1. a small platelike body, especially a blood platelet.


platelet British  
/ ˈpleɪtlɪt /

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

platelet Scientific  
/ plātlĭt /
  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.


Other Word Forms

Noun Inflected Forms

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.

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Vocabulary lists containing platelet

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

He spent nine days on a ventilator and 18 days on dialysis, during which time doctors gave him blood, platelet and plasma transfusions.

From Salon Jun. 22, 2026

As my blood counts fluctuated, and infections threatened, our middle sibling, Art Landro, provided platelet support collected from his blood.

From The Wall Street Journal Apr. 19, 2026

While the results are promising, platelet factor 4 alone is not expected to reverse aging throughout the entire body or significantly extend human lifespan.

From Science Daily Dec. 31, 2025

Though the effect was strong, platelet factor 4 won't be a silver bullet that reverses the aging of all tissues and prolongs the lifespan of elderly human patients alone, Pinho said.

From Science Daily Dec. 31, 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

Once you donate blood, it is taken to a lab, where it is separated into three components: platelets, red blood cells, and plasma.

From Slate May 9, 2026

The common thread is that malignant cells overtake the marrow—the tissue that produces white blood cells to fight infection, red blood cells to carry oxygen, and platelets to prevent bleeding.

From The Wall Street Journal Apr. 19, 2026

A similar trial for blood platelets is being planned.

From BBC Sep. 17, 2024

Blood and platelets must be immediately available, yet they have a short shelf life, according to Daniel Parra, a spokesman for the American Red Cross.

From New York Times Jun. 15, 2024

At some point, you’d have to run into water or rock or the earth’s platelets or something.

From "Gregor the Overlander" by Suzanne Collins

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