From Longman Dictionary of Contemporary Englishpie in the skypie in the skyPROBABLYsomething good that someone says will happen, but which you think is impossible or unlikely Hope of a cure is just pie in the sky. → mud pie, pie chart, → easy as pie at easy1(1), → eat humble pie at humble1(6), → have a finger in every pie at finger1(7), → be as nice as pie at nice(11) → pie
Examples from the Corpus
pie in the sky• But that's all pie in the sky.• What used to be pie in the sky when you die has, quite rightly, become pie now, please.• Building a baseball field downtown is just pie in the sky right now.• Any talk of getting a reasonable response from the terrorists is just pie in the sky.• So much pie in the sky, she remembered thinking later.• Do not be deceived into throwing away a decent offer in pursuit of pie in the sky.• Eventual payment was promised at the rate of 5Op per deal, but this proved pie in the sky.• I was promised the pie in the sky by and by. 