Massive fan of sci-fi endorsing Banks (5)
I believe the answer is:
fiend
'massive fan' is the definition.
'fiend' can be an answer for 'fan' (thesaurus). I am not sure about the 'massive' bit.
'sci-fi endorsing banks' is the wordplay.
I cannot quite understand how this works, but
'fi' is within the answer.
The remaining letters 'end' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for fiend that I've seen before include "Devilish person" , "Evil supernatural being" , "Operatic super-soprano" , "Demon, ogre" , "monster" .)