Conservative's tired out glory (6)
I believe the answer is:
credit
'glory' is the definition.
(thesaurus)
'conservative's tired out' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'out' is an anagram indicator (out can mean wrong or inaccurate).
'tired' is an anagram of 'redit'.
'c'+'redit'='CREDIT'
(Other definitions for credit that I've seen before include "Believe the advance of money" , "gives you a good result in examination" , "Believe; good reputation" , "Believe; acknowledgement" , "Commendation; tick" .)