also leucocyte, 1860, via French leucocyte, from Greek leuko-, comb. form of leukos "white" (see light (n.)) + -cyte (see cyto-).[leukocyte etymology, leukocyte origin, 英语词源]
"Designating types or stages of leukaemias and related diseases in which the leucocyte count in the blood is not elevated; especially in aleukaemic leukaemia", Late 19th cent.; earliest use found in American Journal of the Medical Sciences. From a- + leukaemic, after French aleucémique or its etymon German aleukämisch.