To be out of order or reversed; very confused or mixed up; completely fouled up or wrong.

'Ass' refers to the rear end or buttocks, and 'backwards' means reversed. The phrase suggests that something is happening the wrong way, with the rear coming first. ('Ass' is an impolite word, so be careful using this phrase.)

Synonym: snafu

To do something totally wrong or stupid, whether intentionally or not. Something that is the opposite of itself. To be stupid or slow.

to do something the exact opposite way that any normal person would do it. to defy logic by carrying out an act with no hope of accomplishing anything purposeful.
purposely doing something wrong to prove a really stupid point.

1. moving backwards

2. hopelessly misguided, doing everything wrong

Doing things the wrong way. Starting from the wrong end.

1. doing something the wrong way

A goddamned piece of shit that doesn't do the thing it's fucking supposed to is "assbackwards".