Nick cannot choose trousers (5)
I believe the answer is:
notch
'nick' is the definition.
(synonyms)
'cannot choose trousers' is the wordplay.
'trousers' says the answer is hidden in the clue (to trouser can mean to steal or take).
'NOTCH' is hidden in the letters of 'cannot choose'.
(Other definitions for notch that I've seen before include "Incision; indentation" , "Nick - incision" , "Point or degree in a scale" , "Carved incision" , "Tallying incision" .)