The most common and most likely answer to this crossword clue is the 10 letter word EFFRONTERY
I've seen this crossword clue in The Times
E
F
F
R
O
N
T
E
R
Y
More clues leading to the result EFFRONTERY
- English reformer throttling leading European's neck
- Fry often gets tipsy around the Queen — sheer impudence!
- Ferry often arranged brass
- Offer entry free — what arrogance
- The nerve of Rockefeller Center housing a political group, extremely reactionary
- Impudence, unsettling ref, often leads to red/yellow
- Disrespect ruined entry offer
Buddy explains!

The straight part
We know that "neck" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case neck = effrontery.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 EFFRONTERY mean?
EFFRONTERY noun- Insolent and shameless audacity.
- An act of insolent and shameless audacity.