What is another word for castle in the air?
Pronunciation: [kˈasə͡l ɪnðɪ ˈe͡ə] (IPA) 
Castle in the air is a phrase used to describe a lofty, unrealistic or impractical plan or idea. However, there are synonyms that can be used to convey a similar meaning. One alternative is pipe dream, which refers to a fanciful idea that is unlikely to happen. Another is pie in the sky, which describes a proposal that is unattainable or unrealistic. A third option is wild-goose chase, which means pursuing a futile or meaningless task. You could also use daydream, which is a pleasant and imaginative fantasy that isn't grounded in reality. Lastly, the phrase airy-fairy can refer to something that is impractical, vague, or lacking substance.
