Private cleaned tins out (11)
I believe the answer is:
clandestine
'private' is the definition.
(I've seen this before)
'cleaned tins out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'cleaned'+'tins'='cleanedtins'
'cleanedtins' anagrammed gives 'CLANDESTINE'.
(Other definitions for clandestine that I've seen before include "through the backdoor" , "Send a client (anag) - covert" , "Undercover" , "backroom" , "Surreptitious" .)