The most common and most likely answer to this crossword clue is the 4 plus 6 letter word NOVA SCOTIA
I've seen this crossword clue in Financial Times
N
O
V
A
S
C
O
T
I
A
More clues leading to the result NOVA SCOTIA
- Star Glaswegian recalled fine area around Halifax
- In review: small bit of land where O Canada‘s sung, principally, alongside river!
- Latin clue for a stoic found in this province
- Free, so vacation in province
- Vacations at sea taking in Ontario’s premier island
- Vacation so fantastic in part of Canada
- Number on course breaking through in province
- Necktie one’s found in river going over province
- Where you might find vacation so unusual?
- Love getting into vacations to travel somewhere in the Atlantic
Buddy explains!

The straight part
We know that "island" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case island = nova scotia.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.