The most common and most likely answer to this crossword clue is the 8 letter word VUVUZELA
I've seen this crossword clue in The Times
V
U
V
U
Z
E
L
A
More clues leading to the result VUVUZELA
Buddy explains!
The straight part
We know that "Cape Horn" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cape horn = vuvuzela.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 VUVUZELA mean?
VUVUZELA noun- A trumpet-shaped horn, now usually plastic, that produces a loud buzzing sound.