assbackwards

American  

[as-bak-werdz] / ˈæsˈbæk wərdz /

Or assbackward

adverb

Slang: Sometimes Vulgar.

1. in an order or way reverse from the usual.

   You've sewn the sleeve on assbackwards.

2. 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.

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Etymology

Origin of assbackwards

First recorded in 1935–40; ass ² + backwards