castle in the air

noun phrase
variants: or less commonly castle in Spain

Definition of castle in the air

: an impracticable project : daydream

First Known Use of castle in the air

1566, in the meaning defined above

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Time Traveler for castle in the air

Time Traveler

The first known use of castle in the air was in 1566

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Dictionary Entries Near castle in the air

castle-guard

castle in the air

Castleman disease

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Cite this Entry

“Castle in the air.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/castle%20in%20the%20air. Accessed 3 Jul. 2022.

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