Noun | 1. | ![]() histiocytic leukaemia, histiocytic leukemia, monoblastic leukaemia, monocytic leukaemia, monocytic leukemia cancer of the blood, leucaemia, leukaemia, leukemia - malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancer |