dendritic cell

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An antigen-presenting leukocyte found in the skin, mucosa, and lymphoid tissues that initiates a primary immune response by activating lymphocytes and secreting cytokines.
• noun A cell that has branching processes.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biology Any cell, having branching processes, that forms part of the mammalian immune system