Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun castle_in_the_air
1 sense of castle in the air
Sense 1
reverie, revery, daydream, daydreaming, oneirism, air castle, castle in the air, castle in Spain -- (absentminded dreaming while awake)
=> dream, dreaming -- (imaginative thoughts indulged in while awake; "he lives in a dream that has nothing to do with reality")