Walk out on barren land (6)
I believe the answer is:
desert
This clue is a double definition.
'walk out on' is the first definition.
(I've seen this before)
'barren land' is the second definition.
(thesaurus)
(Other definitions for desert that I've seen before include "Sweet" , "Abandon, waterless area" , "Barren area" , "Arid area of sand" , "Abandon in arid place" .)