top and bottom; up and down; upper and lower ends
Refers to the two vertical sides, directions, or ends of something: which part is up and which part is down.
This pattern has no top or bottom, so you can use it without worrying about orientation.
箱のうえしたを確認してから棚に置いてください。
Check the top and bottom of the box before putting it on the shelf.
noun which may take the genitive case particle 'no', noun
upside down; with top and bottom reversed
Used as a noun or の-modifying expression for an upside-down state, especially in constructions such as 上下になる. More explicit alternatives such as 逆さま or 上下逆 are also common.
See also: 上下になる
あ、この地図はうえしたになっているよ。
Oh, this map is upside down.
Check which side of the box is up before you carry it.
I stuck the photo on upside down by mistake.