Archipelago unit (5)
'archipelago unit' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for isle that I've seen before include "one ringed in the main?" , "Small bit of land surrounded by water" , "eg Skye" , "Piece of land in water" , "being impossible without water" .)
'archipelago unit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for islet that I've seen before include "Piece of land in e.g. river" , "Little bit of land" , "Detached territory" , "Ait or key" , "named after Langerhans?" .)