Pronunciation: (ku-nal'),[key] —n., v.,-nalled or -naled, -nal•ling or -nal•ing.
—n. 1. an artificial waterway for navigation, irrigation, etc.
2. a long narrow arm of the sea penetrating far inland.
3. a tubular passage or cavity for food, air, etc., esp. in an animal or plant; a duct.
4. channel; watercourse.
5. Astron.one of the long, narrow, dark lines on the surface of the planet Mars, as seen telescopically from the earth.