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Definitions

castles in the air

ADJECTIVE
fanciful
Synonyms
STRONGEST
absurd bizarre extravagant fantastic fantastical fictional imaginative offbeat preposterous unreal whimsical
WEAK
aerial blue-sky capricious chimerical curious dreamlike fabulous fairy-tale fancied fictitious fictive flaky floating ideal illusory imagined incredible kinky legendary mythical notional on cloud nine pie in the sky pipe dream poetic shadowy suppositious visionary wild
Antonyms
STRONGEST
normal reasonable sensible usual
WEAK
grave ordinary real serious sincere unfanciful unimaginative unromantic
NOUN
reverie
Synonyms
STRONGEST
contemplation fantasy meditation trance
STRONG
absorption abstraction detachment dreaminess dreaming inattention muse musing pensiveness phantasy preoccupation study thought trip woolgathering
WEAK
absent-mindedness castle-building fool's paradise head trip mind trip pipe dream
Antonyms
WEAK
nightmare
NOUN
vision
Synonyms
STRONGEST
aspect conception dream fantasy foresight idea ideal imagination insight outlook perspective point of view understanding view
STRONG
angle astuteness daydream discernment divination facet fancy farsightedness foreknowledge ideality intuition keenness muse nightmare penetration phantasm prescience retrospect slant standpoint trip
WEAK
breadth of view head trip mental picture pie in the sky pipe dream
Antonyms
STRONGEST
being existence ignorance reality substance truth
WEAK
actuality fact sightlessness

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Briceño: Something that I always valued about Cookman was that he never sold us any castles in the air.

From Los Angeles Times • Dec. 4, 2025

They're giddy at having two women pledge to make their sundry castles in the air become real.

From Salon • Mar. 26, 2021

“You can be building castles in the air that have no reference to reality,” Mr. Kesler added.

From New York Times • Aug. 5, 2017

“If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them.”

From Washington Post • Jul. 12, 2017

In the Scientific Revolution, Bacon and Descartes were amongst those with plans for thoroughgoing intellectual change, but their plans were castles in the air, and neither of them imagined what Newton would achieve.

From "The Invention of Science" by David Wootton