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

The straight part
We know that "Van" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case van = forefront.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 FOREFRONT mean?
FOREFRONT noun- The leading position or edge.
- To bring to the forefront; to emphasize, or focus on.