- sulcus (n.)
- plural sulci, "fissure between convolutions of the brain," 1833, from medical use of Latin sulcus "furrow, trench, ditch, wrinkle," apparently literally "the result of plowing," from PIE *selk- "to pull, draw" (source also of Greek holkos "furrow," Old English sulh "plow," Lithuanian velku "I draw").