Tired out by Conservative's reputation? (6)
I believe the answer is:
credit
'reputation?' is the definition.
(thesaurus)
'tired out by conservative's' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'by' means one lot of letters go next to another.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'tired' anagrammed gives 'redit'.
'redit' put after 'c' is 'CREDIT'.
(Other definitions for credit that I've seen before include "Acknowledgement of a contributor" , "'Give ...... where ...... is due'" , "Favourable balance - belief" , "Praise; tick" , "Have faith" .)