The most common and most likely answer to this crossword clue is the 8 letter word BRASHEST
I've seen this crossword clue in The Guardian
B
R
A
S
H
E
S
T
More clues leading to the result BRASHEST
Buddy explains!
The straight part
We know that "Most impudent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most impudent = brashest.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 BRASHEST mean?
BRASHEST adjective- (of people or behaviour) Overly bold or self-assertive to the point of being insensitive, tactless or impudent; shameless.
- (of actions) Overly bold, impetuous or rash.
- (of things) Bold, bright or showy, often in a tasteless way.
- Brittle (said e.g. of wood or vegetables).