The most common and most likely answer to this crossword clue is the 7 letter word ASPERSE
I've seen this crossword clue in Financial Times
A
S
P
E
R
S
E
More clues leading to the result ASPERSE
- Shakespeare’s slander?
- Slander – talk ultimately coming from nasty speakers
- Criticise cast not taking sides, essentially
- When soft language is used to denigrate
- Like, essentially, to spread malicious rumours
- Slander in A Bug’s Life? Pixar films’ executive ultimately seizing power
- Malign when by itself
- Slander from venomous creature, Irish
- Make false accusations when blue
- Slander from rude speakers without a hint of kindness
Buddy explains!

The straight part
We know that "Slander" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case slander = asperse.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 ASPERSE mean?
ASPERSE verb- To sprinkle or scatter (liquid or dust).
- To falsely or maliciously charge another; to slander.