The most common and most likely answer to this crossword clue is the 9 letter word THICKNESS
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More clues leading to the result THICKNESS
Buddy explains!

The straight part
We know that "body" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case body = thickness.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 THICKNESS mean?
THICKNESS noun- The property of being thick (in dimension).
- A measure of how thick (in dimension) something is.
- A layer.
- The quality of being thick (in consistency).
- The property of being thick (slow to understand).