Sound anchorage on a Greek island (6)
I believe the answer is:
rhodes
'a greek island' is the definition.
(Rhodes is a Greek island)
'sound anchorage' is the wordplay.
'sound' indicates a 'sounds like' (homophone) clue.
'anchorage' becomes 'roads' (roads is a kind of anchorage).
'roads' sounds like 'RHODES'.
'on' is the link.
(Other definitions for rhodes that I've seen before include "Horsed around on the Greek island" , "Hordes visit the Greek island" , "Greek island - British-born South African statesman" , "See 21 Down" , "Hordes go to the Greek island" .)