'Genesis' - an erotic novel (8)
I believe the answer is:
creation
'genesis' is the definition.
(genesis means something's creation)
'an erotic novel' is the wordplay.
'novel' is an anagram indicator (letters in a new or novel order).
'an'+'erotic'='anerotic'
'anerotic' anagrammed gives 'CREATION'.
(Other definitions for creation that I've seen before include "production" , "Something that has been made" , "New product" , "The bringing into existence of something" , "Beginning event" .)