Girl in farce, 'The Ladykillers' (5)
I believe the answer is:
ethel
'girl' is the definition.
(I've seen this before)
'in farce the ladykillers' is the wordplay.
'in' says the answer is hidden in the clue.
'ETHEL' can be found hidden inside 'farce the ladykillers'.
(Other definitions for ethel that I've seen before include "woman" , "Perhaps a Barrymore" , "chapel" , "- Merman, US musical comedy star" , "- Barrymore, actress" .)