The most common and most likely answer to this crossword clue is the 8 letter word LESBIANS
I've seen this crossword clue in The Guardian
L
E
S
B
I
A
N
S
More clues leading to the result LESBIANS
Buddy explains!

The straight part
We know that "Aegean islanders" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case aegean islanders = lesbians.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 LESBIANS mean?
LESBIANS noun- A homosexual woman, one who is mostly or exclusively sexually or romantically attracted to other women.
- A homosexual female animal.