It's hateful having nothing and five hundred debts (6)
I believe the answer is:
odious
'it's hateful' is the definition.
('odious' can be similar in meaning to 'hateful')
'nothing and five hundred debts' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'and' means one lot of letters go next to another.
'five hundred' becomes 'd' ('D' can be a synonym of 'five hundred').
'debts' becomes 'ious'.
'o'+'d'+'ious'='ODIOUS'
'having' acts as a link.
(Other definitions for odious that I've seen before include "Really hateful, detestable" , "Contemptible" , "Detestable, execrable" , "'Hateful, repulsive (6)'" , "Really hateful, abhorrent" .)