Partners excluded from a naturist survey (5)
I believe the answer is:
audit
'survey' is the definition.
(thesaurus)
'partners excluded from a naturist' is the wordplay.
'partners' becomes 'sn'.
'excluded from' indicates named letters should be taken away.
'naturist' becomes 'nudist' ('nudist' can be a synonym of 'naturist').
'a'+'nudist'='anudist'
'anudist' with 'sn' taken away is 'AUDIT'.
(Other definitions for audit that I've seen before include "Financial check" , "Formally examine" , "vetting of books" , "Financial investigation" , "Investigate" .)