Such nights figured in a fabulous story (7)
I believe the answer is:
arabian
'fabulous story' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'such nights figured in a' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for arabian that I've seen before include "Saudi, perhaps" , "These Nights provide fairy tales" , "Middle Easterner; horse" , "Like Saudi, Yemeni, etc" , "Sea in the northwestern part of the Indian Ocean" .)