Money used to accommodate American relative (6)
I believe the answer is:
cousin
'relative' is the definition.
(I've seen this before)
'money used to accommodate american' is the wordplay.
'money' becomes 'coin' (I've seen this before).
'used to accommodate' means one lot of letters goes inside another.
'american' becomes 'us'.
'coin' going around 'us' is 'COUSIN'.
(Other definitions for cousin that I've seen before include "Aunt/uncle's child" , "Aunt's/uncle's child" , "Relation, could be kissing" , "An uncle or aunt's child" , "Son or daughter of an uncle or aunt" .)