expression, noun which may take the genitive case particle 'no'
confused; chaotic; jumbled; upside-down
Describes a state of great confusion or disorder, often with things turned upside down or in a jumble. Used as a set phrase, often with の to modify a noun.
With preparations for moving, the room is in utter chaos.
突然の来客で家中が上を下へになった。
The whole house was turned upside down by the unexpected visitor.
Literally 'up to down', this phrase evokes the image of things being flipped or mixed up, leading to the meaning of confusion or chaos.