Set out to stop honest administrator (7)
I believe the answer is:
trustee
'administrator' is the definition.
(type of administrator of a trust)
'set out to stop honest' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'to stop' indicates putting letters inside.
'honest' becomes 'true' (associated in meaning).
'set' anagrammed gives 'ste'.
'ste' put inside 'true' is 'TRUSTEE'.
(Other definitions for trustee that I've seen before include "Member of a fund's governing board" , "Legal guardian" , "Legal administrator" , "Person who holds and administers property for another - sounds reliable" , "financial overseer" .)