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Synonyms

white blood cell

American  

noun

  1. any of various nearly colorless cells of the immune system that circulate mainly in the blood and lymph and participate in reactions to invading microorganisms or foreign particles, comprising the B cells, T cells, macrophages, monocytes, and granulocytes.

white blood cell British  

noun

  1. a nontechnical name for leucocyte

"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
white blood cell Scientific  
/ wīt /

  1. Any of various white or colorless cells in the blood of vertebrate animals, many of which participate in the inflammatory and immune responses to protect the body against infection and to repair injuries to tissues. White blood cells are formed mainly in the bone marrow, and unlike red blood cells, have a cell nucleus. The major types of white blood cells are granulocytes, lymphocytes, and monocytes. White blood cells are far less numerous in the blood than red blood cells, but their amount usually increases in response to infection and can be monitored as part of a clinical assessment.

  2. Also called leukocyte

Etymology

Origin of white blood cell

First recorded in 1885–90

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.

After the birth of her second child, her doctor noticed her white blood cell count was high.

From Los Angeles Times • Jan. 2, 2026

Doctors at Columbia Presbyterian Hospital in New York first noticed Schlossberg’s irregular white blood cell count hours after she gave birth to her second child in May 2024, according to the essay.

From The Wall Street Journal • Dec. 30, 2025

The human digestive system relies on two main kinds of macrophages, a type of specialized white blood cell, to maintain intestinal health.

From Science Daily • Nov. 3, 2025

When her white blood cell count dropped dangerously low she had to spend time in hospital but she says doctors did everything they could to treat her symptoms.

From BBC • Oct. 31, 2025

He wasn’t able to go to school for weeks on end when his white blood cell counts were low, so I was basically his sole source of entertainment.

From "Drums, Girls, and Dangerous Pie" by Jordan Sonnenblick

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.