Shirabe
幻想
Common Noun Irregular Transitive
Español jmdict
1
noun (common) (futsuumeishi)noun or participle which takes the aux. verb surutransitive verb ilusiones
English jmdict
1
noun (common) (futsuumeishi)noun or participle which takes the aux. verb surutransitive verb fantasy;illusion;vision;dream
Your idea is, as it were, a castle in the air.