Sea veteran (3,4)
I believe the answer is:
old salt
'sea veteran' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for old salt that I've seen before include "'Long-time sailor (3,4)'" , "Experienced sailor of saline sort" , "Experienced sailor with stale sodium chloride?" , "Tar" , "'Ancient mariner (3,4)'" .)