Point rose out that’s deteriorated (5)
I believe the answer is:
worse
'deteriorated' is the definition.
(thesaurus)
'point rose out' is the wordplay.
'point' becomes 'w' (West).
'out' indicates an anagram (out can mean wrong or inaccurate).
'rose' is an anagram of 'orse'.
'w'+'orse'='WORSE'
'that's' is the link.
(Other definitions for worse that I've seen before include "less moral?" , "More severe; less well" , "more unpleasant" , "Of poorer quality" , "Less satisfactory" .)