The most common and most likely answer to this crossword clue is the 9 letter word CONFLATED
I've seen this crossword clue in The Daily Telegraph
C
O
N
F
L
A
T
E
D
Buddy explains!

The straight part
We know that "Put together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case put together = conflated.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 CONFLATED mean?
CONFLATED verb- To bring (things) together and fuse (them) into a single entity.
- To mix together different elements.
- (by extension) To fail to properly distinguish or keep separate (things); to mistakenly treat (them) as equivalent.