The most common and most likely answer to this crossword clue is the 8 letter word CAVESSON
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The straight part
We know that "Noseband" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case noseband = cavesson.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 CAVESSON mean?
CAVESSON noun- A part of a horse's bridle that consists of a headstall with a noseband. When a martingale is used, it is attached to the horse's head at the cavesson.