macrophage

n. large white blood cell which destroys foreign and potential harmful particles (Biology)

Macrophages (Greek: "big eaters", from makros "large" + phagein "eat") are cells within the tissues that originate from specific white blood cells called monocytes. Monocytes and macrophages are phagocytes, acting in both nonspecific defense (or innate immunity) as well as specific defense (or cell-mediated immunity) of vertebrate animals. Their role is to phagocytose (engulf and then digest) cellular debris and pathogens either as stationary or mobile cells, and to stimulate lymphocytes and other immune cells to respond to the pathogen.
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Noun
1. a large phagocyte; some are fixed and other circulate in the blood stream
(hypernym) phagocyte, scavenger cell
(hyponym) histiocyte

n. macrophage, large white blood cell which destroys foreign and potential harmful particles (Biology)

Type of white blood that takes in (ingests) foreign material. Macrophages are key players in the immune response to foreign invaders of the body, such as infectious microorganisms.