British money concealed by gangster, lingering (8)
I believe the answer is:
sterling
'british money' is the definition.
(I've seen this in another clue)
'concealed by gangster lingering' is the wordplay.
'concealed by' says the answer is hidden in the clue.
'STERLING' is hidden in the letters of 'gangster lingering'.
(Other definitions for sterling that I've seen before include "British currency" , "Genuine - money" , "UK money" , "Of the highest quality" , "banking standard" .)