At right angles to a ship (5)
I believe the answer is:
abeam
'at right angles to a ship' is the definition.
(I've seen this before)
This is all the clue.
(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" .)