The most common and most likely answer to this crossword clue is the 9 letter word DUNGAREES
I've seen this crossword clue in Financial Times
D
U
N
G
A
R
E
E
S
More clues leading to the result DUNGAREES
- Grease smeared on brown trousers
- Manure a Welshman collected — wearing these?
- Greyish-brown grease ruined clothing
- . Use garden rocks and overalls
- A prophet appearing reflective after dropping trousers
- Are exhibitionists disheartened after dropping trousers and more?
- Muck found on a prophet turning up in overalls
- Overalls with muck on are, and sleeveless vest
- Overalls getting messy stuff are finally made spotless
- Clothing for work in manure a discerning person turns over
Buddy explains!

The straight part
We know that "Overalls" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case overalls = dungarees.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 DUNGAREES mean?
DUNGAREES noun- Heavy denim pants or trousers, usually with bib and braces, worn especially as work clothing.