The most common and most likely answer to this crossword clue is the 7 letter word POLLUTE
I've seen this crossword clue in Independent
P
O
L
L
U
T
E
More clues leading to the result POLLUTE
- Foul pole vault leaving Virginia seething
- Dirty election, with one politician getting off charge
- Harm the environment when the 13 writer holds up Jethro, perhaps
- Make bad cutback with instrument
- Damage ozone layer? Cut back emissions firstly, crave less — small input
- Dirty election must be oddly disregarded
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 POLLUTE mean?
POLLUTE verb- To make something harmful, especially by the addition of some unwanted product.
- To make something or somewhere less suitable for some activity, especially by the introduction of some unnatural factor.
- To corrupt or profane
- To violate sexually; to debauch; to dishonour.
- Polluted; defiled.