- sulcus (n.)
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- 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").