At year's end, fled to a Scottish island (5)
I believe the answer is:
arran
'scottish island' is the definition.
(island off the coast of Scotland)
'at year's end fled to a' is the wordplay.
'at' is a charade indicator (letters next to each other).
'end' suggests the final letters.
'fled' becomes 'ran' (ran away).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
The final letter of 'year' is 'r'.
'r' next to 'ran' is 'rran'.
'rran' put after 'a' is 'ARRAN'.
(Other definitions for arran that I've seen before include "Isle near Firth of Clyde" , "Scottish island" , "Scottish territory" , "Firth of Clyde island" .)