The most common and most likely answer to this crossword clue is the 12 letter word EXTERMINATES
E
X
T
E
R
M
I
N
A
T
E
S
Buddy explains!

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 EXTERMINATES mean?
EXTERMINATES verb- To kill all of (a population of pests or undesirables), usually intentionally.
- To bring a definite end to; finish completely.