• Blood cells that are devoid of hemoglobin, capable of amoeboid motion and phagocytosis, and act as the principal components of the immune system.
  CDISC Terminology
  Clinical Data Interchange Standards Consortium (CDISC), 2021
• A type of immune cell. Most leukocytes are made in the bone marrow and are found in the blood and lymph tissue. Leukocytes help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are leukocytes.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• White blood cell, specifically a colorless cell with a nucleus, found in blood and lymph; leukocytes are capable of amoeboid movement; they can produce antibodies and move through the walls of vessels to migrate to sites of injury, where they isolate and destroy dead tissue, foreign protein and bacteria.
  CRISP Thesaurus
  National Institutes of Health, 2006
• White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• White blood cell, a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility, and defends the body against infection and disease by ingesting foreign materials and cellular debris, by destroying infectious agents and cancer cells, or by producing antibodies. A...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2020