The most common and most likely answer to this crossword clue is the 1 plus 3 plus 3 letter word A BAD JOB
I've seen this crossword clue in The Guardian
A
B
A
D
J
O
B
More clues leading to the result A BAD JOB
- A radio personality in a hairstyle that’s a mess
- Ailurophile’s top facilitator of tunes, one shilling rings … and turkey?
- What’s unfortunate answer by American jock in dock?
- Twelve old pennies to secure Bill and Jack? You might expect this, then
- Sailor on a date’s struggle to make the best of it?
- Sailor Bill – a patient bloke – trying to make the best of it?
Buddy explains!

The straight part
We know that "a mess" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a mess = a bad job.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.