The most common and most likely answer to this crossword clue is the 6 letter word IMPISH
I've seen this crossword clue in Financial Times
I
M
P
I
S
H
More clues leading to the result IMPISH
- Naughty Zulus stop talking!
- Everyman’s quiet, regularly kitschy and rascally
- Warriors quiet and wicked
- This writer’s impatient expression characterised by mischief?
- One politician’s desireis mischievous
- Impatient expression after one monkey started being mischievous
- Naughty one a bit like a politician
- Naughty setter’s rubbish!
- Wicked? Yours truly is? Pooh-pooh!
- Mischievous Zulu band’s quiet
Buddy explains!

The straight part
We know that "wicked" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wicked = impish.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 IMPISH mean?
IMPISH adjective- Mischievous; of or befitting an imp.