castle in the air
1. 空中楼阁
What he is talking about is just a castle in the air.
他所谈论的一切, 只不过是空中楼阁。
习惯用语a castle in the air1.空中楼阁, 空[梦, 幻]想a castle in Spain1.空中楼阁, 空[梦, 幻]想build castles in the air1.抱幻想, 存梦想build castles in Spain1.抱幻想, 存梦想built like a castle1.体格健壮的(指马)cloud castle1.空想; 不切实际的计划castles in Spain1.空想, 白日梦; 架空的计划