Caledonian author and his novel (8)
I believe the answer is:
scottish
'caledonian' is the definition.
(I've seen this before)
'author and his novel' is the wordplay.
'author' becomes 'scott' (I can't explain this - if you can you should give a lot more credence to this answer).
'and' says to put letters next to each other.
'novel' indicates an anagram.
'his' with letters rearranged gives 'ish'.
'scott'+'ish'='SCOTTISH'
Can you help me to learn more?
(Other definitions for scottish that I've seen before include "Costs hit this nationality badly" , "from 18 [MORAY], say?" , "northern folk" , "Caledonian" , "So stitch up to be like Angus or Jock" .)