The most common and most likely answer to this crossword clue is the 8 plus 5 letter word SHOULDER BLADE
I've seen this crossword clue in The Daily Telegraph
S
H
O
U
L
D
E
R
B
L
A
D
E
More clues leading to the result SHOULDER BLADE
- Take responsibility for knife in part of the body
- Mistaking one end of mastoid for the other, accept responsibility for flat bone
- Breaking old rule, bashed bone
- Must Queen be shielding boy that’s part of body?
- Bear somehow able to swallow top of dog and bone
- Must youngster, consumed by beer, broadcast some of joint?
Buddy explains!

The straight part
We know that "part of body" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of body = shoulder blade.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 SHOULDER BLADE mean?
SHOULDER BLADE noun- Either of the large flat bones at the back of the shoulder.