Rested poorly in Sahara (6)
I believe the answer is:
desert
'sahara' is the definition.
(thesaurus)
'rested poorly' is the wordplay.
'poorly' indicates an anagram (a poor spelling).
'rested' is an anagram of 'DESERT'.
'in' acts as a link.
(Other definitions for desert that I've seen before include "See 23" , "Kalahari, e.g." , "Abscond from forces" , "barren tract" , "Abandon in Sahara" .)