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

The path to chemotherapy began with a 1943 wartime disaster in Bari, Italy, where sailors exposed to mustard gas showed severely depleted white blood cell counts.

From The Wall Street Journal • Apr. 24, 2026

Inflammatory indicators included C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and platelet count.

From Science Daily • Apr. 13, 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

Their large-scale data analysis pointed to a distinct molecular state in a type of white blood cell known as CD14+ monocytes, which play a key role in immune defense.

From Science Daily • Mar. 26, 2026

However, the nodes in John’s neck were much harder, and his white blood cell count much higher, than would have been the case in someone with TB.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French