Infeasible

Your idea is absolutely infeasible.

Rural electrification was finally coming, even though for years nay-sayers had said it was economically infeasible.

"With magic in limited use and hidden, it was possible to enhance the various magic resistances of humans, and to keep certain forms of magic from being possible. If magic enters common usage, this interference becomes infeasible."

Labour's Shadow Transport Secretary Louise Haigh said: "There is a cost-of-living crisis, and the Prime Minister blew nearly £1m of public money on an utterly infeasible vanity project. That's enough to fill 18,000 potholes. This shows the Tories' sheer disrespect for public money."