Gorge or ravine (6)
I believe the answer is:
canyon
This clue is a double definition.
'gorge' is the first definition.
(I know that gorge can be written as canyon)
'ravine' is the second definition.
(I know that canyon is a type of ravine)
(Other definitions for canyon that I've seen before include "Deep, steep-sided valley" , "The Grand . . . . . . of Colorado is a natural phenomenon in USA" , "Deep fissure" , "'Deep ravine, gorge (6)'" , "Gulf" .)