Gorge? Ravine? Defile? I don’t know the answer (4)
I believe the answer is:
pass
I believe this is a quintuple definition!!
'gorge?' is the first definition.
(gorge is a kind of pass)
'ravine?' is the second definition.
(pass can mean a ravine)
'defile?' is the third definition.
(defile is a kind of pass)
'i don't know' is the fourth definition.
(e.g. response in a quiz)
'the answer' is the fifth definition.
(thesaurus)
(Other definitions for pass that I've seen before include "I've no idea" , "Transfer" , "Overtake - get through" , "Elapse; mountain route" , "Cross-mountain route; permit" .)