Old sailor (3,3)
I believe the answer is:
sea dog
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">old sailor</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sea dog that I've seen before include "Experienced sailor (colloq.)" , "Experienced mariner" , "'Old salt (3,3)'" , "Ancient Mariner" , "Old or experienced sailor" .)