(n.) A short ridge connecting two higher elevations or mountains; the pass over such a ridge.

abysm abyss arroyo box canyon breach break canyon cavity chap chasm check chimney chine chink cleft cleuch clough comb coulee couloir crack cranny crevasse crevice cut cwm defile dell dike ditch donga draw esker excavation fault fissure flaw flume fracture furrow gap gape gash gorge groove gulch gulf gully hogback hole horseback incision joint kame kloof leak moat notch nullah opening pass passage ravine rent ridge rift rime rupture saddle saddleback scissure seam slit slot spine split trench valley void wadi