Awful to rent out (6)
I believe the answer is:
rotten
'awful' is the definition.
(thesaurus)
'to rent out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'to'+'rent'='torent'
'torent' is an anagram of 'ROTTEN'.
(Other definitions for rotten that I've seen before include "Morally despicable" , "Decomposed" , "Informally, very much" , "Decayed, putrid" , "unpleasant" .)