The most common and most likely answer to this crossword clue is the 9 letter word WORKMATES
I've seen this crossword clue in The Guardian
W
O
R
K
M
A
T
E
S
More clues leading to the result WORKMATES
Buddy explains!
The straight part
We know that "Collaborators" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case collaborators = workmates.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 WORKMATES mean?
WORKMATES noun- Somebody with whom one works; a coworker.