Sulcus

n. furrow, groove

Sulcus (pl. sulci) is a Latin word :used in Latin to refer to a groove, furrow or trench.used in planetary geology to refer to subparallel grooves and ditches formed by geological processes. See Sulcus (geology)used in medicine, botany and zoology to refer to grooves, crevices, and furrows. e.g., superior pulmonary sulcus See Sulcus (anatomy)for sulci specifically in the brain, see sulcus (neuroanatomy).
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Noun
1. (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain
(hypernym) fissure
(hyponym) fissure of Rolando, Rolando's fissure, central sulcus, sulcus centralis
(classification) anatomy, general anatomy

(n.)
A furrow; a groove; a fissure.
  

From the Latin for a groove, furrow, or trench. In medicine, there are many sulci (plural of sulcus) as, for example, the superior pulmonary sulcus.