The most common and most likely answer to this crossword clue is the 10 letter word GRENADINES
I've seen this crossword clue in Financial Times
G
R
E
N
A
D
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S
Buddy explains!

The straight part
We know that "Caribbean group" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case caribbean group = grenadines.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 GRENADINES mean?
GRENADINES noun- A cordial syrup made from pomegranates.
- A dilute drink made from this syrup.
- A thin gauzy fabric of silk or wool, used for women's clothing and men's woven luxury ties.
- (formerly a trade name) A dyestuff consisting essentially of impure fuchsine.