“Fiction has the interesting double sense of a kind of Imaginative Literature and of pure (sometimes deliberately deceptive) invention… A general use, ranging between a consciously formed hypothesis (‘mathematical fictions’ 1579) and an artificial  and questionable assumption (‘of his own fiction’), was equally common. Fictitious, from C17, ranged from this to the sense of deceptive invention; the literary use required the later fictional. The popularity of novels led to a curious C20 back-formation, in library and book-trade use, in non-fiction (at time made equivalent to ‘serious’ reading…)

Novel, now so nearly synonymous with fiction, has its own interesting history. The two senses now indicated by the noun (prose fiction) and the adjective (new, innovating, whence novelty) represent different branches of development from Latin novus – new. Until C18 novel, as a noun, carried both senses: (i) a tale; (ii) what we now call, with the same sense, news…

(In) Fielding: – ‘What novel’s this? – Faith! It may be a pleasant one to you.’

It was from this range of senses that novelist meant successively any kind of innovator (C17), a newsmonger (C18) and a writer of prose fiction.” (Keywords)