The most common and most likely answer to this crossword clue is the 6 plus 3 letter word NUMBER TWO
I've seen this crossword clue in The Times
N
U
M
B
E
R
T
W
O
More clues leading to the result NUMBER TWO
- Insensitive bully wrote for deputy
- On freezer, a brace or vice
- Union man without deputy
- Carrying medical qualification, doctor went with our deputy
- Stool, might one sit beside chair?
- Deputy‘s short cut
- Buzz notably with anaesthetic to suppress
- Vice-captain won’t worry about Wood not starting
- Vice a shade into seedy town
- Dump deputy
Buddy explains!

The straight part
We know that "vice" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vice = number two.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.