The low fellow has evidence of debts – bearing much interest! (7)
I believe the answer is:
curious
'aeur bearing much interest' is the definition.
I can't tell whether this definition defines the answer.
'the low fellow has evidence of debts' is the wordplay.
'the low fellow' becomes 'cur' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'has' says to put letters next to each other.
'evidence of debts' becomes 'IOUs' (IOU's or I Owe You's).
'cur'+'ious'='CURIOUS'
Can you help me to learn more?
(Other definitions for curious that I've seen before include "Eager to learn something" , "Intrigued" , "Odd - inquisitive" , "Strange - inquisitive" , "Odd or eager to know" .)