Relative Fleming, say, rubbed out in Russian fiction novel (5,6)
I believe the answer is:
first cousin
'relative' is the definition.
(first cousin is a kind of relative)
'fleming say rubbed out in russian fiction novel' is the wordplay.
I cannot quite understand how this works, but
'in' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for first cousin that I've seen before include "Family member" , "relative" .)