Why is a Monocyte called Monocyte?

Monocytes are so-named because they are the largest of the peripheral blood mononuclear cells (PBMCs). The word "mono-" means "single" and "cyte" means "cell", as in "mononuclear". Mononuclear cells are cells that have a single nucleus, as opposed to multinucleated cells, which have multiple nuclei.

Monocytes are a type of white blood cell that is produced in the bone marrow and circulates in the blood. They are part of the immune system and help to protect the body from infection. Monocytes can leave the bloodstream and enter tissues, where they differentiate into macrophages and dendritic cells. Macrophages are large phagocytic cells that engulf and destroy foreign particles, such as bacteria and viruses. Dendritic cells are antigen-presenting cells that help to activate T cells, which are important for cell-mediated immunity.