myelocyte
noun
my·e·lo·cyte ˈmī-ə-lə-ˌsīt 
: a bone-marrow cell
especially : a motile cell with cytoplasmic granules that gives rise to the granulocytes of the blood and occurs abnormally in the circulating blood (as in myelogenous leukemia)
myelocytic
ˌmī-ə-lə-ˈsi-tik
adjective 
Word History
Etymology
borrowed from German Myelocyt, from myelo- myelo- + -cyt -cyte
Note: In the given sense the term was apparently introduced by Paul ehrlich in "Ueber die Bedeutung der neutrophilen Körnung," Charité-Annalen, 12. Jahrgang (1887), p. 295. In the text of the article the word is spelled Myklozythen (plural) for expected Myelocythen, presumably as a result of a typesetting error.
First Known Use
1891, in the meaning defined above
Medical Definition
myelocyte
noun
my·e·lo·cyte ˈmī-ə-lə-ˌsīt
: a bone marrow cell
especially : a motile cell with cytoplasmic granules that gives rise to the blood granulocytes and occurs abnormally in the circulating blood (as in myelogenous leukemia)