[F. couloir colander, passage, lobby, the steep incline down which timber is precipitated on a mountain side:—late L. cōlātōrium, f. cōlāre, in F. couler to flow.]
A steep gorge or gully on a mountain side: first used in reference to the Alps (see quot. 1856).
1855. J. D. Forbes, Tour Mt. Blanc, ii. 21. It descended a narrow couloir from the Aiguilles Rouges.
1856. Ruskin, Mod. Paint., IV. V. i. § 9. 22, note. ‘Couloir’ is a good untranslateable Savoyard word for a place down which stones and water fall in storms; it is perhaps deserving of naturalization.
1860. Tyndall, Glac., I. § 7. 47. Up this couloir we proposed to try the ascent.
