One fled from the Islands (4)
I believe the answer is:
aran
'islands' is the definition.
(I have seen 'Irish islands' mean 'aran' so perhaps 'islands' could also mean 'aran')
'one fled' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'fled' becomes 'ran' (ran away).
'a'+'ran'='ARAN'
'from the' acts as a link.
(Other definitions for aran that I've seen before include "Irish islands" , "Irish style of knitwear" , "Galway Bay isle" , "islands near 9 [GALWAY]" , "traditional type of knitwear" .)