At right angles to a ship (5)
I believe the answer is:
abeam
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">at right angles to a ship</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for abeam that I've seen before include "In a line at right angles to a vessel's length" , "from side to side on voyage?" , "neither fore nor aft?" , "Set across" , "across centre" .)