Pick lost niece out (9)
I believe the answer is:
selection
'pick' is the definition.
(I know that pick can be written as selection)
'lost niece out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'lost'+'niece'='lostniece'
'lostniece' is an anagram of 'SELECTION'.
(Other definitions for selection that I've seen before include "Choice, pick" , "Act of choosing" , "Horse tipped for betting" .)