Relative keeps us in money (6)
I believe the answer is:
cousin
'relative' is the definition.
(cousin is a kind of relative)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for cousin that I've seen before include "US icon is an odd relative" , "Aunt/uncle's child" , "Kinsman, generally (archaic)" , "Family relative" , "An aunt's or uncle's child" .)