assbackwards

or ass·back·ward

[ as-bak-werdz ]
/ ˈæsˈbæk wərdz /

adverb Slang: Sometimes Vulgar.

in an order or way reverse from the usual: You've sewn the sleeve on assbackwards.
in a manner incongruously or preposterously counter to what is customary, probable, or feasible: The plan fell apart because everything leading up to it was handled assbackwards.

Origin of assbackwards

First recorded in 1935–40; ass2 + backwards

Words nearby assbackwards