Pirate’s associate arriving aboard vessel (6)

I believe the answer is:
parrot
'pirate's associate' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'arriving aboard vessel' is the wordplay.
'arriving' becomes 'arr' (abbreviation used in transport).
'aboard' indicates putting letters inside.
'vessel' becomes 'pot' (type of container).
'arr' inserted into 'pot' is 'PARROT'.
Can you help me to learn more?
(Other definitions for parrot that I've seen before include "Ape" , "Tropical bird noted for mimicking speech" , "Brightly coloured tropical bird" , "Imitate like tropical bird" , "Mechanically repeat; bird" .)
