Barren land that's rested perhaps (6)
I believe the answer is:
desert
'barren land' is the definition.
(thesaurus)
'rested perhaps' is the wordplay.
'perhaps' indicates an anagram.
'rested' anagrammed gives 'DESERT'.
'that's' is the link.
(Other definitions for desert that I've seen before include "Kalahari, e.g." , "sands" , "Walk out on" , "Abandon, desolate area" , "barren tract" .)