WordNet (r) 3.0 (2006):

haematopoiesis
    n 1: the formation of blood cells in the living body (especially
         in the bone marrow) [syn: hematopoiesis,
         haematopoiesis, hemopoiesis, haemopoiesis,
         hemogenesis, haemogenesis, hematogenesis,
         haematogenesis, sanguification]