Odd, but for one dodgy loan (11)
I believe the answer is:
exceptional
'odd' is the definition.
(thesaurus)
'but for one dodgy loan' is the wordplay.
'but' becomes 'except' (I've seen this before).
'for one' becomes 'i' (I've seen this in other clues).
'dodgy' indicates anagramming the letters (a dodgy or wrong order of the letters).
'loan' with letters rearranged gives 'onal'.
'except'+'i'+'onal'='EXCEPTIONAL'
(Other definitions for exceptional that I've seen before include "Out of the ordinary" , "Very unusual" , "Unusually good" , "Outstanding; not typical" , "Extraordinary!" .)