pheo·chro·mo·blast \|fēō+\noun alsopheo·chro·mo·cy·to·blast\ˌfēōˌkrōmōˈsīd.əˌblast\ Etymology:pheochromoblast from pheochrome + -o- + -blast; pheochromocytoblast from pheochromocyte + -o- + -blast : an embryonic cell destined to give rise to chromaffin tissue especially of the adrenal medulla