one of the two roots of a spinal nerve, called ventralroot 前根という脊髄神経 - EDR日英対訳辞書
any of the important motor nerves on each side of the central nervous system that run from the sensorimotor areas of the cortex through the brainstem to motor neurons of the cranial nerve nuclei and the ventralroot of the spinal cord
大脳皮質の感覚運動野から脳幹を通じて脳神経核の運動ニューロンと脊髄神経の前根までのどちら側かの神経系にある重要な運動神経のいずれか - 日本語WordNet