1) An immature nerve cell 2) Embryonic cell 3) Formative cell 
A neuroblast is a dividing cell that will develop into a neuron often after a migration phase. Neuroblasts differentiate from neural stem cells and are committed to the neuronal fate. The main difference between a neuroblast and a neuron is the ability to divide; neuroblasts can still undergo mitosis, whereas neurons are postmitotic. Neuroblasts a...
(from the article `nervous system, human`) ...system originate from the ventricular zone of the neural tube—that is, the layer of neuroepithelial cells lining the central cavity of the tube. ...
<embryology> Cells arising by division of precursor cells in neural ectoderm (neurectoderm) that subsequently differentiate to become neurons. ... (16 Dec 1997) ... 
(noor´o-blast) an embryonic cell from which nervous tissue is formed.
Cells arising by division of precursor cells in neural ectoderm (neurectoderm) that subsequently differentiate to become neurons.
Type: Term Pronunciation: nū′rō-blast Definitions: 1. An embryonic nerve cell.
An neuroblast is an embryonic nerve cell.
[n] - a cell from which a nerve cell develops
noun a cell from which a nerve cell develops
an immature nerve cell.