The most common and most likely answer to this crossword clue is the 7 letter word CLUTTER
I've seen this crossword clue in Financial Times
C
L
U
T
T
E
R
More clues leading to the result CLUTTER
- One doing my job sober gets in a mess!
- Mess left with knife around?
- Mess is complete after carnival emptied out
- After class, complete confusion
- Absolute mess
- Messy accumulation of toxic gas, say
- Chaos as leak's starting to appear in boat
- Mess left aboard Coast Guard vessel
- Disorderly mess left in sailing vessel
- Mess left inside ship
Buddy explains!

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 CLUTTER mean?
CLUTTER noun- A confused disordered jumble of things.
- Background echoes, from clouds etc., on a radar or sonar screen.
- A group of cats; the collective noun for cats.
- Clatter; confused noise.
- To fill something with clutter.
- To clot or coagulate, like blood.
- To make a confused noise; to bustle.
- To utter words hurriedly, especially (but not exclusively) as a speech disorder (compare cluttering).