Lose oar at sea in spray (7)
I believe the answer is:
aerosol
'spray' is the definition.
(thesaurus)
'lose oar at sea' is the wordplay.
'at sea' is an anagram indicator.
'lose'+'oar'='loseoar'
'loseoar' anagrammed gives 'AEROSOL'.
'in' is the link.
(Other definitions for aerosol that I've seen before include "Mister" , "What makes mist" , "Pressurized container" , "can, probably" , "Container with device for releasing contents as fine spray" .)