逆さか

noun, used as a prefix, noun

inverse; reverse; opposite

Used as a prefix or noun to indicate something is inverted, reversed, or contrary to the usual direction or order. Common in compounds like 逆さま (upside down) and 逆方向 (opposite direction).

• 本ほんを逆さかさに置おいた。

  I placed the book upside down.

• 旗はたを逆さかさに掲かかげた。

  They hung the flag upside down.