Spinning top, novel problem (7)
I believe the answer is:
dilemma
'problem' is the definition.
(a dilemma is a problem)
'spinning top novel' is the wordplay.
'spinning' is a reversal indicator.
'top' becomes 'lid' (lid is a kind of top).
'novel' becomes 'Emma' (novel by Jane Austen).
'lid' reversed gives 'dil'.
'dil'+'emma'='DILEMMA'
(Other definitions for dilemma that I've seen before include "Difficult-choice situation" , "I'm lamed - it's a puzzle" , "Difficult situation - may have horns" , "Unpalatable choice" , "Difficult decision" .)