The most common and most likely answer to this crossword clue is the 3 plus 5 letter word ABU DHABI
I've seen this crossword clue in Independent
A
B
U
D
H
A
B
I
More clues leading to the result ABU DHABI
- A half-hearted religious founder born originally in sheikhdom
- A friend from the US with limited custom in Arab city
- Going round Dubai? Bah! It’s along the coast
- A half-hearted religious leader seeking men and women in the capital
- Hot and bothered at first in Dubai — moving, but not far!
- Rating given to hotel in resort of Dubai – or Dubai’s neighbour
- Middle Eastern capital where one follows early growth in biblical king
- A short practice involving little growth in capital
- Friend wearing a nun’s outfit docked in the capital
- A friend in America with endless addiction to emirate
Buddy explains!
The straight part
We know that "Island Capital/Capital" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case island capital/capital = abu dhabi.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.