The most common and most likely answer to this crossword clue is the 9 plus 6 letter word BEEFSTEAK TOMATO
I've seen this crossword clue in The Daily Telegraph
B
E
E
F
S
T
E
A
K
T
O
M
A
T
O
More clues leading to the result BEEFSTEAK TOMATO
Buddy explains!
The straight part
We know that "Fruit avoided by vegetarians?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fruit avoided by vegetarians? = beefsteak tomato.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.