Twice Frenchman in bad deals crashed (7)
I believe the answer is:
slammed
'crashed' is the definition.
(I've seen this before)
'twice frenchman in bad deals' is the wordplay.
'twice' says to double the letters.
'frenchman' becomes 'm' (abbreviation for Monsieur - like 'Mr').
'in' indicates putting letters inside.
'bad' indicates anagramming the letters.
'm' duplicated is 'mm'.
'deals' is an anagram of 'slaed'.
'mm' inserted into 'slaed' is 'SLAMMED'.
(Other definitions for slammed that I've seen before include "crashed" , "Criticised" , "Shut forcefully with loud noise" .)