Flat broke and on the rocks (5)
I believe the answer is:
stony
'flat broke' is the definition.
(thesaurus)
'on the rocks' is the wordplay.
'on' is an insertion indicator (as in clothing 'on' a person).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'rocks' becomes 'sony' (I am not sure about this - if you are sure you should believe this answer much more).
't' put into 'sony' is 'STONY'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for stony that I've seen before include "made of marble?" , "Hard for those who are barefoot" , "Cold, unfeeling" , "penniless" , "Rocky" .)