The phrase "a fictional conceit" is correct and usable in written English.
It can be used to refer to an imaginative idea or concept that is not based in reality, often found in literature or art.
Example: "The novel's central theme revolves around a fictional conceit that explores the nature of time travel."
Alternatives: "an imaginative construct" or "a literary device".
As a fictional conceit, that aspect is fairly high-concept.
New Yorkers know that time travel is not a fictional conceit.
"If the characters are emerging out of the book seeming like puppets or exercises in what is essentially a fictional conceit rather than a human conceit, then the whole book will fail," she said.
But, like many cell-phone novelists, she takes the disguise a great deal further, and makes of her identity a fictional conceit: the spectral, recessive wallflower author whose impression on the world, for all the confessions contained in her novel, is almost illegibly faint.
Very occasionally, those touches threaten to cloud the book with a misplaced sense of camp, but the danger is only ever fleeting, given that much of its power comes from plain-spoken passages that suggest straight reportage rather than any fictional conceit.
In Dear Mr M Koch turns the hoary old metaphor into a complex fictional conceit.
Why Everyone Owes Everyone and No One Can Pay (Allen Lane), is that it understands the financial crisis as a literary event, a fantastical piece of magical realism, in which the self-delusion of debt became a shared fictional conceit.
The play The Reckoning of Kit and Little Boots, by Nat Cassidy, examines the lives of the Elizabethan playwright Christopher Marlowe and Caligula, with the fictional conceit that Marlowe was working on a play about Caligula around the time of his own murder.
That's the fictional conceit of An Imagined Museum – but it opens at a historical moment that itself has an unreal quality of nightmare.
So, clearly, my real neighbor on my recent Aspen-Denver flight was not my fictional conceit of Mr. Smokepuff.
Much of this - embellished by plenty of fictional conceits - is chronicled in a new film called Grand Theft Parsons, a micro-budget caper movie that puts Johnny Jackasss" Knoxville in the role of Phil Kaufman.
