Book number five doesn't take the whole shelf! (5)

I believe the answer is:

novel

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'book' is the definition.
(I know that novel is a type of book)

I can't explain the rest of the clue.

(Other definitions for novel that I've seen before include "Romance - new" , "Book of prose fiction" , "A work of fiction of new kind" , "New piece of fiction?" , "Scoop, say" .)

I've seen this clue in the Evening Standard.

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