The most common and most likely answer to this crossword clue is the 6 letter word SLOVEN
I've seen this crossword clue in The Times
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More clues leading to the result SLOVEN
Buddy explains!
The straight part
We know that "Messy person's" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case messy person's = sloven.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 SLOVEN mean?
SLOVEN noun- A habitually dirty or untidy man or boy; the male equivalent of slattern, or slut.
- A low, base, lewd person.
- An immoral woman.