沟; 胼胝体沟; 凹; 槽
Sulcus \Sul"cus\, n.; pl. {Sulci}. [L., a furrow.] A furrow; a groove; a fissure.
sulcus n : (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain [also: {sulci} (pl)]