The most common and most likely answer to this crossword clue is the 5 letter word LOBES
I've seen this crossword clue in The Guardian
L
O
B
E
S
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 = lobes.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 LOBES mean?
LOBES noun- Any projection or division, especially one of a somewhat rounded form.
- A clear division of an organ that can be determined at the gross anatomy level, especially one of the parts of the brain, liver or lung.
- A semicircular pattern left on the ice as the skater travels across it.