[geology] A moulin or glacier mill is a roughly circular, vertical to nearly vertical well-like shaft within a glacier through which water enters from the surface. The term is derived from the French word for mill. They can be up to 10 metres wide and are typically found at a flat area of a glacier in a region of transverse crevasses. Mouli...
shaft in a glacier caused by water running down a crack
(French: `mill`), a nearly cylindrical, vertical shaft that extends through a glacier and is carved by meltwater from the glacier`s surface. ...
(à poivre) mill (peppermill); also used for oil and flour mills.
a nearly vertical channel in ice that is formed by flowing water; usually found after a relatively flat section of glacier in a region of transverse crevasses; also called a pothole .
(French, 'mill') A shaft by which supraglacial meltwater enters a glacier to become englacial or subglacial. 
a nearly vertical shaft or cavity worn in a glacier by surface water falling through a crack in the ice.