The most common and most likely answer to this crossword clue is the 9 letter word CLAMOROUS
C
L
A
M
O
R
O
U
S
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The straight part
We know that "Vocal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vocal = clamorous.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 CLAMOROUS mean?
CLAMOROUS adjective- Of or pertaining to clamor.
- Having especially (and often unpleasantly) bright or contrasting colours or patterns.