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.

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white blood cell British  

noun

1. a nontechnical name for leucocyte

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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

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Etymology

Origin of white blood cell

First recorded in 1885–90

Example Sentences

Over time, the glitches in individual cells add up; a single white blood cell from a 100-year-old, we learn, typically contains more than 3,000 mutations.

From The Wall Street Journal • Apr. 20, 2026

The most commonly reported side effect was a decrease in neutrophils, which are a type of white blood cell.

From Science Daily • Apr. 3, 2026

He started chemotherapy soon after the February podcast was recorded and was getting white blood cell injections to help boost his immune system.

From Los Angeles Times • Mar. 30, 2026

Last month, Oscar had T-cells - a type of white blood cell - removed and sent to a lab in Stevenage.

From BBC • Jan. 13, 2026

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