1. Literally, a lack of leukocytes in the blood. The term is generally used to indicate varieties of leukemic disease in which the white blood cell count in circulating blood is normal or even less than normal (i.e., no leukocytosis), but a few young leukocytes are observed; sometimes used more restrictedly for unusual instances of leukemia with no leukocytosis and no young forms in the blood.
2. Leukemic changes in bone marrow associated with a subnormal number of leukocytes in the blood. See Also: subleukemic leukemia.
[G. a- priv. + leukos, white, + haima, blood]