myeloblast
noun
my·e·lo·blast ˈmī-ə-lə-ˌblast 
: a large mononuclear nongranular bone-marrow cell
especially : one that is a precursor of a myelocyte
myeloblastic
ˌmī-ə-lə-ˈbla-stik
adjective 
Word History
Etymology
borrowed from German Myeloblast, from myelo- myelo- + -blast -blast
Note: In the current sense the word is attributed to the Swiss hematologist Otto Naegeli (1871-1938), in "Ueber rothes Knochenmark und Myeloblasten," Deutsche medicinische Wochenschrift, 26. Jahrgang, No. 18 (3 Mai 1900), pp. 287-90.
First Known Use
circa 1904, in the meaning defined above
Medical Definition
myeloblast
noun
my·e·lo·blast ˈmī-ə-lə-ˌblast
: a large mononuclear nongranular bone marrow cell
especially : one that is a precursor of a myelocyte compare leukoblast