Aegean island group (8)
I believe the answer is:
cyclades
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">aegean island group</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for cyclades that I've seen before include "many islands" , "Island group inc. Naxos" , "Aegean island group" , "Greek islands in the southern Aegean" .)