noun
erythroblast
Medical term for a nucleated red blood cell precursor found in bone marrow.
赤芽細胞は骨髄で赤血球に成熟する。
Erythroblasts mature into red blood cells in the bone marrow.
赤血球 is a mature red blood cell, while 赤芽細胞 is an immature precursor.
Compound of 赤芽 (red bud/sprout) + 細胞 (cell), a calque from German 'Erythroblast'.