Extract of novel? Seems otherwise (4)
I believe the answer is:
else
'otherwise' is the definition.
('else' can be a synonym of 'otherwise')
'extract of novel? seems' is the wordplay.
'extract of' indicates the answer is hidden within the clue (I've seen this in other clues).
'ELSE' is hidden within 'novel seems'.
(Other definitions for else that I've seen before include "Alternatively" , "As an alternative" , "In addition; different" , "Other than (what is under consideration)" , "Adverb meaning if not, otherwise" .)