Scrabble tiles key (5)
I believe the answer is:
islet
'key' is the definition.
(both can mean a small island)
'scrabble tiles' is the wordplay.
'scrabble' indicates anagramming the letters (I've seen 'scrabbling' mean this (I've seen this in other clues)).
'tiles' with letters rearranged gives 'ISLET'.
(Other definitions for islet that I've seen before include "Rockall, for example" , "Very small area surrounded by water" , "Piece of land in e.g. river" , "Detached bit of land" , "A small piece of territory" .)