From the sea I returned to the river (4)
I believe the answer is:
aire
'river' is the definition.
(I've seen this before)
'from the sea i returned to the' is the wordplay.
'from' says the answer is hidden in the clue.
'AIRE' is hidden in the letters of 'sea i returned the'.
(Other definitions for aire that I've seen before include "River of the Yorkshire dales" , "Terrier -- Yorkshire area" , "Northern English river, tributary of the Ouse" , "Major river of Yorkshire" , "English flower" .)