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

Lymph nodes are where T cells and B cells encounter foreign invaders and mount a defense response. — Allison Palmer, Charlotte Observer, 29 June 2026

Lymph nodes are where T cells and B cells encounter foreign invaders and mount a defense. — Allison Palmer, Sacbee.com, 29 June 2026

Meanwhile, prototypic B cells made their own separate exit from the macrophage line. — Mrigakshi Dixit, Interesting Engineering, 25 May 2026

Patients also retain antibodies that their B cells made before the treatment, which provide residual protection for a few months. — Amber Dance, ArsTechnica, 17 May 2026

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