外侧 wàicè outer side Origin Definitions Defs Strokes Stroke Words Sentences Sents 外侧沟 wàicègōu lateral sulcus the lateral sulcus or Sylvian fissure in neuroanatomy外侧裂 wàicèliè lateral sulcus the deep fissure on the surface of the brain that separates the frontal and parietal lobes from the temporal lobe; also known as the Sylvian fissure