Air-built
Pronunciation : Air"-built`
Part of Speech : a.
Definition : Defn: Erected in the air; having no solid foundation; chimerical; as, an air-built castle.
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder