'Sulcus' definitions:

Definition of 'sulcus'

From: WordNet
noun
(anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain

Definition of 'Sulcus'

From: GCIDE
  • Sulcus \Sul"cus\, n.; pl. Sulci. [L., a furrow.] A furrow; a groove; a fissure. [1913 Webster]