The most common and most likely answer to this crossword clue is the 9 letter word SEPARATES
I've seen this crossword clue in The Guardian
S
E
P
A
R
A
T
E
S
More clues leading to the result SEPARATES
Buddy explains!

The straight part
We know that "Parts" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case parts = separates.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 SEPARATES mean?
SEPARATES noun- (usually in the plural) Anything that is sold by itself, especially an article of clothing.
- To divide (a thing) into separate parts.
- To disunite from a group or mass; to disconnect.
- To cause (things or people) to be separate.
- To divide itself into separate pieces or substances.
- To set apart; to select from among others, as for a special use or service.