1. (n.) A hollow place in the earth; an abyss; a deep chasm or basin,

2. (n.) That which swallows; the gullet.

3. (n.) That which swallows irretrievably; a whirlpool; a sucking eddy.

4. (n.) A portion of an ocean or sea extending into the land; a partially land-locked sea; as, the Gulf of Mexico.

5. (n.) A large deposit of ore in a lode.

Charybdis Maelstrom abysm abyss aperture arm armlet arroyo back stream backflow backwash backwater bay bayou belt bight boca box canyon breach break broaching canyon cave cavity chap chasm check chimney chink clearing cleft cleuch clough col coulee couloir countercurrent counterflow counterflux cove crack cranny crater creek crevasse crevice cut cwm deep defile dell depth dig diggings dike disclosure ditch donga draw eddy estuary euripus excavation fault fenestra fiord firth fissure fistula fjord flaw flume fontanel foramen fracture frith furrow gap gape gash gat gorge groove gulch gully gurge gut harbor hiatus hole hollow incision inlet interval joint kloof kyle lacuna laying open leak loch lough maelstrom mine moat mouth narrow narrow seas narrows natural harbor notch nullah opening opening up orifice outlet pass passage passageway pit pore quarry ravine reach refluence reflux regurgitation rent rift rime road roads roadstead rupture scissure seam separation shaft slit slot slough sound space split stoma strait straits swirl throwing open trench twirl uncorking unstopping valley void vortex wadi well whirl whirlpool workings yawn yawning abyss