Fab to be somehow associated with iconic sort of series (9)
I believe the answer is:
fibonacci
'sort of series' is the definition.
(as in the Fibonacci sequence)
'fab to be somehow associated with iconic' is the wordplay.
'to be somehow associated with' indicates anagramming the letters.
'fab' mixed up with 'iconic' gives 'FIBONACCI'.
(Other definitions for fibonacci that I've seen before include "Italian mathematician who gave name to sequence" , "Mathematician giving name to a series" , "Thirteenth century Italian mathematician associated with series one, one, two, three, five, eight etc" , "Maths whiz" .)