Let down in dodgy deal (7)
I believe the answer is:
allowed
'let' is the definition.
(to allow something is to let it happen)
'down in dodgy deal' is the wordplay.
'down' becomes 'low' (associated in meaning).
'in' means one lot of letters goes inside another.
'dodgy' is an anagram indicator (a dodgy or wrong order of the letters).
'deal' anagrammed gives 'aled'.
'low' put inside 'aled' is 'ALLOWED'.
(Other definitions for allowed that I've seen before include "Given the chance" , "Permitted and granted" , "Acknowledged" , "Gave permission" , "Owned" .)