In debt over big deal abandoned by a phoney (7)
I believe the answer is:
obliged
'in debt' is the definition.
(I've seen this in another clue)
'over big deal abandoned by a phoney' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'abandoned by' is a deletion indicator.
'phoney' is an anagram indicator.
'big'+'deal'='bigdeal'
'bigdeal' with 'a' removed is 'bigdel'.
'bigdel' with letters rearranged gives 'bliged'.
'o'+'bliged'='OBLIGED'
(Other definitions for obliged that I've seen before include "Duty-bound" , "Bound by a favour rendered" , "Indebted" , "Constrained" , "Grateful - compelled" .)