Scrounge a penny in the prison cell (5)
I believe the answer is:
cadge
'scrounge' is the definition.
(I know that scrounge can be written as cadge)
'a penny in the prison cell' is the wordplay.
'a penny' becomes 'd' (abbreviation e.g. Lsd - pounds, shillings, pence).
'in the' means one lot of letters goes inside another.
'prison cell' becomes 'cage'.
'd' put inside 'cage' is 'CADGE'.
(Other definitions for cadge that I've seen before include "Try to get (something) without paying" , "Scrounge, sponge" , "Scrouge, ask for" , "freeload" , "Scrounge (money, etc)" .)