B cell

noun

: any of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow : b lymphocyte

The glycoproteins produced by B cells, called antibodies or immunoglobulins, recognize and bind free antigens and are responsible for humoral immunity …

—Haruo Saito et al.

… helper T cells that induce the proliferation of the antibody-producing B cells.

—N. A. Mitchison

… patients have no mature B cells circulating in the bloodstream and no antibodies to fight off infections.

—Jean Marx

compare t cell

Examples of B cell in a Sentence

Recent Examples on the Web

Both T cells and B cells contributed to the immune response, suggesting the vaccine provided broad, multi-arm immunity. —New Atlas, 9 Oct. 2025

For decades, scientists thought self-tolerance was primarily established in the parts of the body that make immune cells, such as the thymus for T cells and the bone marrow for B cells. —Aimee Pugh Bernard, The Conversation, 6 Oct. 2025

Progression to rheumatoid arthritis in at-risk individuals is defined by systemic inflammation and by T and B cell dysregulation. —Hannah Millington, MSNBC Newsweek, 24 Sep. 2025

To find those powerful antibodies, scientists sort through B cells, a type of white blood cell that makes millions of different antibodies against a particular pathogen. —Tara Haelle, Scientific American, 23 Sep. 2025

Word History

Etymology

B probably from bursa-derived (produced by the bursa of Fabricius)

First Known Use

1962, in the meaning defined above

Rhymes for B cell

• bel
• belle
• cel
• dell
• dwell
• el
• ell
• fel
• fell
• gel
• gell
• jell

Kids Definition

B cell

noun

ˈbē-ˌsel

: any of the lymphocytes that produce antigen-binding antibodies and that arise and mature in the bone marrow compare t cell

Medical Definition

B cell

noun

: any of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow

called also B lymphocyte

compare t cell