couloir

noun

1. A steep gorge along a mountainside.

   “Those deep, dark slots in a mountain known as couloirs are often the most obvious routes of ascent.”

   “Looking up the face I could see directly into the Japanese and Hornbein couloirs, an almost direct 9000 feet to the summit.”

   “Ascend a long, easy snow couloir back left to the crest of Cassin Ridge at 17700 feet, where there is a campsite.”

   “2002, American Alpine Club Safety Committee, Alpine Club of Canada Safety Committee, Accidents in North American Mountaineering, Issue 55, page 58, When they approached the couloir shortly before 0300, the snow was firm enough for them to use crampons.”

2. (rare)A corridor or passage.

   “It was a hole, in the fence, a large irregular hole, caused by numberless winds, numberless rains, or by a boar, or by a bull, flying, pursuing, a wild boar, a wild bull, blind with fear, blind with rage, or who knows perhaps with carnal desire, crashing at this point, through the fence, weakened by numberless winds, numberless rains. Through this hole I passed, without hurt, or damage to my pretty uniform, and found myself looking about me, for I had not yet recovered my aplomb, in the couloir.”