Bag perfect to hold shilling (5)
I believe the answer is:
purse
'bag' is the definition.
(I've seen this before)
'perfect to hold shilling' is the wordplay.
'perfect' becomes 'pure' ('pure' can be a synonym of 'perfect').
'to hold' indicates putting letters inside.
'shilling' becomes 's'.
'pure' placed around 's' is 'PURSE'.
(Other definitions for purse that I've seen before include "Contract, crease" , "bag for loose change" , "Prize in sporting contest" , "Super (anag.)" , "Compress (lips)" .)