Fools almost hurting valuer (8)
I believe the answer is:
assessor
'valuer' is the definition.
(thesaurus)
'fools almost hurting' is the wordplay.
'fools' becomes 'asses' (ass is a kind of fool).
'almost' means to remove the last letter (most of the word but not all of it).
'hurting' becomes 'sore' ('sore' can be a synonym of 'hurting').
'sore' with its last letter removed is 'sor'.
'asses'+'sor'='ASSESSOR'
(Other definitions for assessor that I've seen before include "One who judges" , "One estimates the value of property" , "Person who tests" , "Legal adviser" , "One values property" .)