Seabird perched on a pole at rear of ship (6)
I believe the answer is:
astern
'at rear of ship' is the definition.
(I've seen this before)
'seabird perched on a pole' is the wordplay.
I cannot quite see how this works, but
'seabird' could be 'ern' (I've seen this in another clue) and 'ern' is found within the answer.
'a' is found in the answer.
'pole' could be 's' (abbreviation for South, as in South Pole) and 's' is present in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for astern that I've seen before include "Aft" , "Toward the back of a boat" , "Behind the back of a ship" , "Nautically behind" , "back for sailors" .)