yea couloir means hallway in french, so ive always thought of it as having to do with having rock walls on either side, and i would also typically think coulies being longer than chutes. If you want a solid definition of what a real couloir is look up some of the stuff in places like chamonix.
A couloir (from the French word meaning "passage" or "corridor,") is a narrow gully with a steep gradient in a mountainous terrain. A couloir may be a seam, scar, or fissure, or vertical crevasse in an otherwise solid mountain mass. Though often hemmed-in by sheer cliff walls, couloirs may also be less well-defined, often simply being a line of broken talus or scree ascending the mountainside and bordered by trees or other natural features. Couloirs are especially significant in winter months when they may be filled in with snow or ice, becoming much more noticeable than in warmer months when the majority of the snow and ice may recede. These physical features make the use of couloirs popular for both skiing and mountaineering.
This. Most 'couloirs' I've seen or skied have been pretty open. They're certainly bordered areas, but not to the extent of chutes. Chutes are generally very enclosed areas (typically for short distances) that you can either make jump turns or straight line. Couloirs can be very open... think of chutes as two close vertical lines you need to ski between and couloirs as something looking like \ /.
Disagree strongly about the width aspect - many couloirs have very narrow cruxes or are consistently narrow, requiring jump turns and such. I would agree that with bigger vertical something is more likely to be described as a couloir rather than chute. Generally though there's a lot of overlap and chute is a more vague term IMO.
yea i agree on the width part...the two lines in this are both couloirs, the one on the lookers left obviously is, but the one from the peak, although it has a 70cm crux, is still very much considered a couloir...granted it does have about 1300m of vertical drop