from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A visionary project or scheme; a day-dream; an idle fancy; a pipe dream; any plan, desire, or idea that is unlikely to be ever realized; a near impossibility.
from the GNU version of the Collaborative International Dictionary of English
- n. a visionary project; a baseless scheme; an air castle; -- sometimes called a castle in Spain (F. Château en Espagne).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. absentminded dreaming while awake
Sorry, no etymologies found.
One of the mighty geological contortions for which the southern Tien Shan are famous had dislocated the strata through ninety degrees into the vertical, creating a castle in the air unassailable except on foot, cradling a walnut forest in its plateau.