Lines from across the silver sea (5)
I believe the answer is:
verse
'lines' is the definition.
(I've seen this before)
'from across the silver sea' is the wordplay.
'from' indicates the answer is hidden within the clue.
'VERSE' is hidden in the letters of 'across silver sea'.
(Other definitions for verse that I've seen before include "Part of hymn" , "Section of a poem" , "Stanza; poetry" , "Poetry, a poem" , "few lines of writing?" .)