The most common and most likely answer to this crossword clue is the 6 letter word CORPUS
I've seen this crossword clue in The Daily Telegraph
C
O
R
P
U
S
Buddy explains!

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 CORPUS mean?
CORPUS noun- A collection of writings, often on a specific topic, of a specific genre, from a specific demographic or a particular author, etc.
- (specifically) Such a collection in form of an electronic database used for linguistic analyses.
- A body, a collection.
- Synonym of long primer