Definition of "air-castle" []

• A castle in the air; a day-dream; a visionary scheme. See castle. (noun)

The Century Dictionary (Public Domain)

• "Emperor of China, his room was ornamented with a picture of Confucius, before which he burned scented wood; and hanging over it was an air-castle, with the motto, "God is Love.""
• "Many an air-castle did we rear that night which the lapse of years have laid in the dust."
• "The college girl cannot marry at this impulsive, air-castle age."