Merriam-Webster Collegiate Dictionary - lymphoblast

 noun  Etymology: International Scientific Vocabulary  Date: circa 1909 a lymphocyte that has enlarged following stimulation by an antigen, has the capacity to recognize the stimulating antigen, and is undergoing proliferation and differentiation either to an effector state in which it functions to eliminate the antigen or to a memory state in which it functions to recognize the future reappearance of the antigen  • ~ic adjective