Body of water east of Dublin (5,3)
I believe the answer is:
irish sea
'body of water east of dublin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for irish sea that I've seen before include "It separates Ireland from Britain" , "Local arm of Atlantic" , "Main" , "Waters around IOM" , "Man's situation" .)