(n.) A hole or spot in a volcanic or other region, from which fumes issue.

abysm abyss arroyo box canyon breach break canyon cavity chap chasm check chimney corner chink chute cleft cleuch clough col coulee couloir country rock crack cranny crevasse crevice cut cwm defile dell deposit dike ditch donga draw excavation fault fender fire screen fireboard fireguard fireplace fireside fissure flaw flue flue pipe flume fracture fumarole funnel furrow gangue gap gape gash gorge groove gulch gulf gully hearth hearthstone hob hole hub incision ingle inglenook ingleside joint kloof leak lode lodestuff matrix mineral deposit moat notch nullah opening ore bed pass passage pay dirt ravine rent rift rime rupture scissure seam shoot slit slot smokehole smokeshaft smokestack split stack stock stovepipe trench valley vein void wadi