Narrow canyon (6)
(Other definitions for ravine that I've seen before include "Steep-sided gorge" , "Deep narrow gorge with steep sides" , "Type of gorge" , "Canyon" , "'Deep, steep valley (6)'" .)
'narrow canyon' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gorge that I've seen before include "Make a pig of oneself" , "Swallow greedily" , "Defile; stuff oneself" , "not fast" , "Overindulge" .)