Associate of the Port of London Authority? (3)
I believe the answer is:
pal
'associate' is the definition.
(a pal is a friend)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for pal that I've seen before include "Bud" , "China" , "Brother" , "Mate, informal friend" , "Close friend" .)