The most common and most likely answer to this crossword clue is the 9 letter word REPELLANT
R
E
P
E
L
L
A
N
T
More clues leading to the result REPELLANT
Buddy explains!
The straight part
We know that "With which you’d drive off large insect" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with which you’d drive off large insect = repellant.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 REPELLANT mean?
REPELLANT noun- Someone who repels.
- A substance used to repel insects, other pests, or dangerous animals.
- A substance or treatment for a fabric etc to make it impervious to something.
- Tending or able to repel; driving back.
- Repulsive, inspiring aversion.
- Resistant or impervious to something.