canyon(redirected from Nanyon)
Also found in: Dictionary, Thesaurus, Medical.
canyonSee Mars, surface features; valley, lunar.
a deep river valley with very steep, often perpendicular, walls and a narrow floor, usually completely occupied by theriverbed. One of the largest canyons in the world is the GrandCanyon of the Colorado River in the USA (length, over 320 km;depth, to 1, 800 m).