Wiktionary
promegakaryocyte
n. (context biochemistry English) A precursor cell for a megakaryocyte, arising from a megakaryoblast.
Wikipedia
Promegakaryocyte
A promegakaryocyte is a precursor cell for a megakaryocyte, arising from a megakaryoblast.
The developmental stages of the megakaryocyte are: CFU-Me ( pluripotential hemopoietic stem cell or hemocytoblast) → megakaryoblast → promegakaryocyte → megakaryocyte.