To talk utter nonsense; to speak of things that are illusory, baseless, or without foundation in reality.
他提出的那些想法，简直是梦中说梦，完全不切实际。
The ideas he proposed were simply talking nonsense, completely impractical.
Next Idiom
To talk utter nonsense; to speak of things that are illusory, baseless, or without foundation in reality.