The most common and most likely answer to this crossword clue is the 8 letter word SLAPDASH
I've seen this crossword clue in The Sunday Telegraph
S
L
A
P
D
A
S
H
More clues leading to the result SLAPDASH
- Disorganised friends in retreat run
- Hasty Scotch added to second round
- Careless hit and run
- Careless mates upset by crash
- Careless hit-and-run
- Careless husband follows pathetic chums back
- Careless vivacity follows second drink
- Sorry friends upset hotel being messy
- Hit-and-run careless
- Messy outcome of hit-and-run?
Buddy explains!

The straight part
We know that "sloppy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sloppy = slapdash.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.
What does SLAPDASH mean?
SLAPDASH verb- To apply, or apply something to, in a hasty, careless, or rough manner; to roughcast.
- Produced or carried out hastily; haphazard; careless.
- In a hasty or careless manner.
- Directly, right there; slap-bang.
- With a slap; all at once; slap.