Was a smasher but penniless (5)
I believe the answer is:
broke
'penniless' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for broke that I've seen before include "Shattered" , "Impecunious" , "Completely out of money" , "Ordinal number" , "Moneyless" .)